Geosites in Reykjanes

Arnarsetur is part of one remarkable geological formation of modern times and is mostly undisturbed. It is a short monogenetic volcanic fissure with scoria and spatters craters, formed in an eruption integral to the Reykjanes Fires, a volcano-tectonic episode from 1210 to 1240. The fissure is two kilometres in length and the lava formations that originate from it cover 20 square kilometres. They are rugged and contain lava tubes and remains of human activity. The name Arnarsetur means Eagle's nest and derives from a pair of eagles that lived in the area before. The Reykjanes fires from 1210 to 1240 AD were the last volcanoes to erupt on the peninsula before Fagradalsfjall in 2021. These fissure swarms produced intense eruptions with curtains of fire. The initial stage of Arnarseturhraun is largely buried under later activity.   The historical records mention some submarine eruptions offshore Reykjanes or by the coastline, part of the metabolism was in the sea causing the island of Eldey (fire island) to arise a few nautical miles from the coast.  Heavy ash appeared and spread a black, fine-grained layer over the Reykjanes peninsula, which nowadays makes the age of lava or human remains comparable.  How to get there? Arnarsetur is located north of the town Grindavik. It can be reached from Grindavíkurvegur, road no. 43. The exit is about halfway from Reykjanesbraut (41) towards Grindavík. Nearby: Snorrastaðartjarnir , Bláa Lónið, Svartsengi  

Three lakes in the hyaloclastite Ice Age ridges Vesturháls and Sveifluháls, contain groundwater. Djúpavatn is partly a crater lake, close to Djúpavatnsleið road, Spákonuvatn crater lake to the Sogin-geosite and Grænavatn to a marked path across Sveifluháls. 

An ancient fishing outfit and a trading post just south of Stafnes. It was one of the harbours of the Danish Trade Monopoly posts comprising Hafnir, Stafnes and Midnes. During the night of January 9th 1799 a catastrophic tidal flood devastated Batsendar. It swept most of the houses away and some of the people barely escaped. Only one old woman drowned. This was the most devastating, tidal flood in the history of the country.   How to get there: Road from Sandgerði to Stafnesi. There is a parking and walk from there until you see ruins of the place and old wall made from rocks. 

Brennisteinsfjöll, or Sulphur Mountains, are a ridge of late Ice Age hyaloclastite mountains. The highest point is the lava shield Kistufell. Brennisteinsfjöll are lined with volcanic fissures that are not much older than Iceland's settlement. A geothermal area is located in the northern part of the mountains, where sulphur was mined around 1880 with little success. The mines are still visible.

Brimketill is a small, naturally carved pool, by marine erosion, at the lava shore edge west of the town of Grindavík. The folklore relates that the pond was regularly occupied by a giantess named Oddný. The viewing platform overlooking Brimketill is just a few steps away from the parking lot starting with a small set of stairs, making the platform inaccessible to wheelchairs. Standing on the platform you risk the possibility of getting soaked as the waves can almost reach the parking lot. Make sure to watch your step while taking in the amazing view and the unrelenting forces of nature. Utmost caution is recommended, especially when travelling with children.   The viewing platform has now been extended and gives visitors a better view over Brimketill. Safety information! There is no safety supervision of the area. Visitors travel at their own risk. The waves can be unpredictable and unexpected. Ocean currents in the area are extremely powerful. Strong blasts of wind can be dangerous and unforeseen. Never leave your child unattended. Hold it at all times on the viewing platform. Entering the sea may be life-threatening. Travel safely in Iceland. SafeTravel.is

Bridge between Europe and North America on Reykjanes Peninsula.   The lava-scarred Reykjanes peninsula lies on one of the world's major plate boundaries, the Mid Atlantic Ridge. According to the continental drift theory the Eurasian and North American tectonic plates are continuously drifting apart with great forces under the gaping rifts. As the plates diverge, linear fractures, known as fissures form due to stresses created by the tension that builds up as the plates move away from each other. The Bridge between two continents at Sandvík is a small footbridge over a major fissure which provides clear evidence of the presence of a diverging plate margin. The bridge was built as a symbol for the connection between Europe and North America. One can cross the continental divide on Leif the Lucky's Bridge and take home a personalised certificate at the Reykjanes information center and Reykjanes Geopark visitor center at Duus Cultural house. 

A rock with three holes, shape like bowls.  Most wanted stop for travellers that had to go to either to Grindavik or Krýsuvík. It is located were these two old roads meet.  The story says that one is for a dog, one for a man and the third for a horse. The water is holy and people could always trust that there would be water to drink.   Location: Short walk from road 427. 

Eldborg is by far the highest of five craters lying along a volcanic fissure in the slopes of Geitafell, and is often called Stóra-Eldborg (Big-Eldborg). It is steep and made of scoria and spatter. A prominent lava channel branches off to the east. Both Stóra-Eldborg and Litla-Eldborg (Small-Eldborg) are protected. It is possible to hike up to Stóra-Eldborg, which is by many considered the most beautiful crater in the Southwest of Iceland, and from there to Litla-Eldborg where one can look straight down the crater. Near Grindavík south of road 427 is Stóra-Eldborg and below the road is Litla-Eldborg. The path to Stóra-Eldborg was recently fixed and a new parking lot was built. New information signs will be put up this summer (2022). 

The grassy field Höskuldarvellir, northwest of Grænadyngja and Trölladyngja, is bordered in the northeast by a large monogenetic scoria and spatter cone. It has been utilized as a gravel mine and has thus been damaged. Steam vents line the surroundings.

A sheer 77 metre high rock protruding out of the sea. It is about 15 km to the south of the southwestern most tip of the Reykjanes peninsula.The structure of Eldey is basaltic hyaloclastites, and it is 0,3 km2 in area. It is the innermost of a chain of skerries standing on a shallow, submarine ridge, which stretches 45 seamiles offshore to the southwest. The name of this chain is Fuglasker or Eldeyjar. One of those skerries was Geirfuglasker, where the last breeding colonies of the Great Auk was located. Geirfuglasker disappeared mostly from the surface during submarine eruptions in 1830.One of the biggest gannet colonies of the world is still surviving on Eldey. According to a count which was made in 1949 the number of gannets breeding there during the summer was 70.000.

Eldvörp is the name of scoria and spatter cones in off-set sections that form a row of ten kilometers, and it's surrounding lava covering 20 square kilometers. It dates back from a volcano-tectonic episode between 1210 and 1240 called the Reykjanes Fires. At the center of Eldvörp there are geothermal features and a single borehole. Women from Grindavík used to bake bread in the steam from the lava and a trail called Brauðstígur, or the Bread trail, leads there from the town. Remains of human activity can be found in various places in Eldvörp.

A eroded subglacial volcano. A section of a small hyaloclastite hill is exposed in the costal cliffs. A dyke named Festi(ladder), evidently the feeder for Festarfjall, passes up through the basement and the Festarfjall sequence, branching towards the base of the lavas. The story say that Festi is a neckless of a woman-troll.  Location: Near highway 427 

On Garðskagi you can find two lighthouses, the older one and also the smaller of the two was once regarded as one of the best lighthouses in Iceland because it stood low and therefore mist was not a problem. Although there was risk of the lighthouse being damaged because of surf and it was sometimes not visible because of seastorm. A new lighthouse was built on Garðskagi in 1944. At 28 metres it is the highest lighthouse in Iceland and was in second place in a survey which Rögnvaldur Guðmundsson supervised concerning the favorite lighthouses of the Icelandic people. Engineer Axel Sveinsson designed the lighthouse but the lighthouse is a radar transponder and used for weather surveilance. The operation of thelighthouse is under the supervision of the Icelandic Maritime Administration.

Place of execution according to an old folk story.  Cliffs, two of which are quite high, with an inlet several fathoms deep between them. A tree between was laied between the two cliffs and men hanged from it a punishment for serious crimes.   Location: About 1 km from Básendar, short walk from road 45

Grænadyngja and Trölladyngja are steep hyaloclastite mountains west of the Sogin geosite. They are surrounded by young volcanic fissures, geothermal sites and beautiful colours. The two mountains are associated with various lava flows, including Afstapahraun close to the Keflavík International Airport main road. Four kilometers on road 41 east from Mt. Keilir.

The mud pools and steam, vents in south-west Reykjanes. The area is close to Reykjanes lighthouse and is collectively named Gunnuhver after a female ghost that was laid there. She had caused great disturbance until a priest set a trap for her and she fell into the spring. This happened about 400 years ago. The mud pools take form where steam from boiling geothermal reservoir water emanates and condenses and mixes with surface water. Accompanying gases such as carbon dioxide and hydrogen sulphide make the water acid. This causes alteration of the fresh lava rock to clay. Steaming of the ground at Reykjanes increased markedly as a consequence of a pressure drawdown in the geothermal reservoir upon the start of production from the reservoir in 2006. Iceland´s largest mud pool at present prominent, highest up in the Gunnuhver group. It is 20 meters wide across a rim of mud, boiling vigorously. Two ramps are located at the Gunnuhver group, on close to Gunnuhver itself where you can look down to the spring and hear the vigorous noise, see the boiling water and feel the power bursting from the ground and the steam on your face. The other ramp is located on Kísilhól a silica hill. From there you have a good view over Gunnuhver group and surroundings. Gunnuhver stands in the heart of the Reykjanes UNESCO Global Geopark where the North Atlantic ridge rises from the ocean, you find 100 different craters and lava fields, bird cliffs, high geothermal areas, black sand beaches, The Bridge Between Continents, geothermal power plants, lighthouses, and exhibitions.

Hafnaberg is a long line of sheer sea lava cliffs south of the old fishing hamlet of Hafnir. Hafnaberg is very popular among hikers and bird watchers as various marine birds nest at the cliffs. A parkingplace is located 4 km from Hafnir on road 44 and from there is a marked path from the road to the cliffs.  Hafnaberg is a geosite in Reykjanes Unesco Global Geopark.

Háleyjarbunga is a small, flat lava shield with a large, 20 to 25 meter deep crater. The shield is at least 9,000 years old. It was formed during a highly effusive lava eruption. The basalt-type is a primitive deep-mantle derived picrite that contains much of the green mineral olivine. Location: The Háleyjarbunga is close to Reykjanes lighthouse on the tip of Reykjanes. A hikingpath is marked form Gunnuhver over the lavafield to Háleyjarbunga.   Háleyjarbunga is a geosite within Reykjanes Unesco Global Geopark.

The spit on which you are standing is named Hópsnes on the west side and Þórkötlustaðanes on the east side. The spit is 2 km long and 1 km wide and was formed 2,800 years ago when lava flowed into the sea. Hópsnes/Þórkötlustaðanes was formed during an eruption from a row of craters named Sundhnúkur located just north of the village of Grindavík. Port conditions in Grindavík are excellent due to this lava flow and the lagoon (Hópið) that formed beside the spit when the sea began to erode the lava and move loose materials. If the spit were not there, the village of Grindavík would probably never have been built. The fact is that it is one of six communities on the Reykjanes peninsula that owes its existence to an eruptive fissure in a volcanic system that is still active. Eruptions could occur in this area at any time. From its earliest days, Grindavík has been one of the main fishing centres in Iceland. Sundhnúkur, from where the lava that formed the spit flowed, has navigation signals showing the route through the gap into the harbour. Travelling around the spit, one can see a number of shipwrecks that have run aground here and in the neighbourhood in the course of the 20th century. There are information signs by some of the wrecks. Both the village and fishing-vessel operations flourished in the early 20th century. Numerous rowing boats and later motor boats were operated from Þórkötlustaðanes. There are a good number of remains of the settlement that is no more, such as entrance cairns, fish-storage huts, ice storages, fish-processing houses, liver-processing and salt huts. The fishing operation moved to the location that is now Grindavík harbour in 1939, when a group of energetic Grindavík residents took it upon themselves to dig a channel through the reef that had hitherto prevented boats from entering the Hópið lagoon. The Hópsnes lighthouse was built in 1928. Today the area is a popular recreational area with a hiking and biking trail. 

The normal fault and tension fracture, Hrafnagjá, is the longest of its kind at the Reykjanes peninsula. It is 12 km long and up to 30 m high. The set of fractures east of Vogar village forms a typical rift valley. Location: Hrafnagjá is visible from Reykjanesbraut (road nr. 41) to Keflavík International Airport. A hikingtrail leads to the location from the parking place by the intersection of the town Vogar. Hrafnagjá is a geosite in the Reykjanes Unesco Global Geopark.

A well known locality for xenolithes. Xenolithesa are gabbroic crystal aggregates related to the host magma. The source of the lava is not known nor is its age.    Location: Near Grindavik, walk from road 427

Hrútagjárdyngja is a 6,000 to 6,500 years old ava shield, plus a lava flow that covers 80-100 sq. km of land. That volume of lava is at least 3 cu. km. Besides a large top carter, the upper part is cut by deep ravines, probably due to magma injections, causing the whole structure to inflate. Location: Sign can be found from road 42 that leads to the shield. 

Ruins of farm partly covered by lava flow. The Húshólmi area is a so called „clearing“ over which the lava Ögmundarhraun didn´t flow during an eruption in the year 1151. The lava came flowing from vulcanic craters on the east side of Núpshlíðarháls hill down to the shore. According to archaeologists, in the western part of the „clearing“ are ruins of the ancient Krýsuvík farm, dated back since before the year 900. Among the ruins are presumably parts of a home, a church and a semetary. Húshólmi is a popular outdoor area and a interesting site worth visiting. 

The church at Hvalsnes was consecrated in 1887. Ketill Ketilsson farmer and ship owner at Kotvogur, who then owned the land at Hvalsnes financed the building of the church. The church is preserved and is completely built of carved stone collected from the local plentiful area of rock. All of the wood in the interior was collected from the shores nearby. Extensive repairs were made to the church in 1945 under the supervision of the architect of the state. One of the most remarkable items of the church is the gravestone of Steinunn Hallgrímsdóttir who died when she was 4 years old in 1649. She was the daughter of Hallgrímur Pétursson Iceland's most important psalmist which at that time served as a priest at the parish in Hvalsnes. The gravestone was lost for a long time but was discovered again in 1964 but it had been used as a part of a walkway leading to the church.The church is still operating today and fits 100 people.   

Hvassahraunskatlar is a hornitos in the Hrútagjá lava shield flow. Hornitos usually form due to powerful degassing at crater edges. These ones, however, came into being approximately 10 km away from the top crater.   Hvassahraunskatlar is a geosite within Reykjanes Unesco Global Geopark.

Katlahraun is lava that flowed about 2,000 years ago and entered the sea. Sudden damming at the shore caused a large, circular lava pond to form. Some lava solidified, but the remaining liquid escaped. The site now contains beautiful and various lava formations.    Katlahraun is a geosite within Reykjanes Uneco Global Geopark.

Keilir is a hyaloclastite mountain. It was created during subglacial eruptions during the ice age. Its shape makes it distinctive; according to geologists, it is probably a crater plug. In spite of its steep slopes, it is not too difficult to climb, and the view from its top on a fine day is to be remembered. Keilir is the most distinctive landmark of Reykjanes and a symbol of the Reykjanes peninsula. On top of the mountain is a concrete table with a view direction map on a metal plate. Location: 4x4 cars can drive on Höskuldarvegi and there is parking at Oddafell and a trail to Keilir.  From Höskuldarvellir there is only a 3 km walk to Keilir. 

Lake between Sveifluháls and Vatnshlíð.  The lake Kleifarvatn is about 10 km². It is the largest of Reykjanes peninsula and the third largest of southern Iceland. It is about 97 m deep and one of the deepest lakes in Iceland.  Its catchment area is small and it has a very limited discharge on the surface. The lake has diminished since year 2000 because of two major earthquakes, which probably opened up fissures at its bottom. In the sixties char fries from Lake Hlidarvatn were released into the lake and have thrived quite well. In the southernmost part a hot water from some hot springs runs into the lake but elsewhere the lake is very cold. A small fishing lodge is located by the lake. Great place for photographers because of the volcanic surroundings of the lake are unique and beautiful. The story says that  a monster in the shape of a worm and size of a medium sized whale lives in the lake.

An open fissure in an oval hyaloclastite mount named Lambafell. The fissure is up to 50 metres deep. It is possible to hike along the entire fissure in the summer time. In the walls of the fissure are excellent outcrops of subglacially formed basaltic pillows.  Location: The walk takes about 1 hour.  Take road to Höskuldarvöllur and then drive down to Trölladyngja. Park at the parking at Eldborg and walk east of Eldborg to Lambafell. 

Inlet created because of a subsidence. Important for birdlife and marine biology.  Location: Near small village Hafnir - short walk from road 44

Patterson Airport was built in 1942 by the usa navy. The airport was mainly used to maintain the aircrafts. Next to the airport can be found Subfossils shells, since 20.000-22.000 years ago. They lived shorly before the Late Glacial Maximum at about 18.000 years age. The sea level at that time was about 5-10 m. The airport was closed 1945.   Location: Road 44 at fence on Patterson. Walk north from old ammunition supplier  

The first lighthouse in Iceland was built on Valahnúkur in Reykjanes inthe year 1878. By 1905 earthquakes and surf had damaged Valahnúkurso much that there was the risk of the lighthouse falling into the sea. A new lighthouse was therefore built in 1907-1908 on Bæjarfell hill in Reykjanes and the old one was demolished with an explosion on april 16th 1908. A survey which Rögnvaldur Guðmundsson supervised in 2007 for the Icelandic Maritime Administration led to the conclusion that Reykjanes lighthouse was the most popular lighthouse among Icelanders. The lightsignal height is 69 meters above sealevel but the actual height of the lighthouse is 26 metres. Reykjanes lighthouse also has a radio beacon with a correction signal. There is carved rock and concrete in the lighthouse. Architect Frederik Kjørboe and engineer Thorvald Krabbe designed the lighthouse. The operationof Reykjanes Lighthouse is under the supervision of the Icelandic Maritime Administration.  

Flat point at the northwestern part of the Reykjanes Peninsula. It is from glacial periods and is between Ytri-Njarðvík and Kirkjuvog.  Rosmhvalur was another name for Walrus and the story says that they used to live there. There is a new sign that shows a good way to drive around Reykjanes. 

One of the oldest and largest lava shield on the Reykjanes peninsula. Formed in late glacial time, about 14.000 years ago, when sea level was about 30 m lower than today.  Only recommend going there on well-equipped jeeps. By foot it is possible to walk on road between Svartsengi and Reykjanes 

Selatangar was a big fishing outfit between Grindavik and Krysuvik. It was abolished after 1880. Extended ruins of the abodes and other houses are still very prominent in the landscape. They have been declared inviolate. During the latter part of the 19th century ghosts started haunting the settlement. Driftwood was in abundance at Selatangar in the past, but less nowadays. The surroundings are grandious, low mountains and lava fields. How to get there: A track for 4wd-vehicles lies down to the ruins on the coast from the road to Isolfsskali.

A pond with good walking paths, picnic facilities and a barbecue. Next to Seltjörn is Sólbrekkuskógur, a small forest, but sheltered and lovely as it is situated hugging small slopes, with interesting rock formations in a few places. Next to the pond is an abandoned building that was raised in 1941, this building was used to harvest ice to keep fish cold.  

A protective wall that lay from Kirkjuból to Útskálar.  The village of Garður at the north tip of the peninsula was named after the wall.  The wall or garður (cognate with English garth), which probably dated from the early days after the settlement, served to keep livestock away from the crops. The wall was broad and tall, built of turf and large rocks. Remnants of it are visible by the old road between Garður and Sandgerði. While today the only reminder of agriculture in the area is fields of grass, several hundred years after the settlement farmers were still cultivating such crops as wheat, oats and barley.   Location: From Útskálakirkja in Garður to Kirkjubólsvelli. By road 45, towards Garðskagalighthouse.

Earthquake fissures in a shield that built up in several eruptions.        In a narrow fissure system. Can find there small caves. It is most common to walk to Skálafell from parking at Gunnuhver. 

A popular recreational area.  Pounds, rich of vegetation and important resting place for migration birds. Next to the pounds is Háibjalli, a 10 m high fault.    Location: Road 43 near Seltjörn and Sólbrekkuskógur. 

Ruins of a shieling(hut), used for cattles during the summer time. The shieling was located in a crater.   Location: Short walk from road 428 (only open summertime). 

A depression in a hyaloclastite ridge. The area is colourful due to intese high temperature alternation and a few mud pools and solfataras.  Location: During summertime it is possible to drive on road Vígdísarvellir (428) on well-equipped cars but it is closed during winter. On winter it is possible to walk from road Krýsuvíkurvegur (42).  

A sheep shelter, round in shape and constructed skilfully from lava rocks. Situated 2-3 km from the former parsonage Kalfatjorn in a direct line from there to Mt Dyngja.  It is about two metres high, 8 m in diameter, and 35 m in circumferance.  The ground inside it is flat and covered with grass.No sources reveal its age, but it is considered to be a few centuries old.  According to the legend, a man named Gudmundur built it for the reverend at Kalfatjorn.  He worked elaborately at the construction, collected stones from the surrounding area to have a large selection to chose from to fit them together as perfectly as possible.  He planned to close it with a cone shaped roof of stones, but the reverend envisioned it higher and more prominent than his church´s steeple and stopped the construction work.  The stone mason left it exactly as we see it today.  It was declared inviolate in 1951.

Two volcanic fissures lie from the sea onto land on the western side of Reykjanes and form a series of craters. These crater series have been named Stampar. The crater series are from two periods. This series lies in the SW-NE direction and follow thereby the most common fissure angle in Reykjanes.   The older formed in an eruption from a fissure that was just under 4 km long around 1,800 to 2,000 years ago.   The younger Stampar crater series formed in the Reykjanes Fires in 1210–1240. The row of craters is around 4 km, and the area of the lava field they produced is approximately 4.6 km2. The two craters closest to the road, named Stampar, are at the north end of the crater row. Further south in the crater row are other sizeable craters such as Miðahóll hill, Eldborg the deeper and Eldborg the shallower. Fishermen in earlier times used all these craters as points of reference when out at sea. Most of the craters, however, are low-lying scoria cones and not very prominent.   It may be noted that during the Reykjanes Fires in 1210–1240, there were four lava flows in the Reykjanes and Svartsengi system, as well as submarine eruptions in the seas off Reykjanes.   The Hundred Crater Trail, a signposted trail, lies partly through the Stampar lava field. The trail starts at Valahnúkur in Reykjanes. The trail also passes through the Reykjanes geothermal zone, past slag and scoria cones, the tuff mountain Sýrfell and on to the Stampar craters. From there, the path lies over rough pahoehoe lava and sand dunes, running from the west side of the crater closest to the road, along the row of craters, on to the seaward side of the Reykjanes Power Plant. The craters along the trail are numerous and fragile.   Walking up onto the crater nearest the road is permitted. It is important, however, to make sure that sensitive natural formations are not disturbed. Location: Road 425 about 2,5 km north of Rauðhólar, short walk from there

A crater row formed in eruption 2.350 years ago. It created natural harbour condtions in the town Grindavík. Sundahnúkur was used as a landmark for the Grindavík harbour in former times. 

One of the five major high temperature areas of the Reykjanes Peninsula. It supplies all of the communities of the Reykjanes Area with hot water for house heating and other purpose. The famous Blue Lagoon comes from the discharge from the power station. Area of green patches north of the hill Svartsengisfell north of the town Grindavík. On summertime the people of Grindavík celebrate there.  

A lava flow formed in an eruption in the year 1151 AD. In that year a 25 km long fissure opened obliquely across the Reykjanes peninsula. The lava field is located in south of ridge Nupshlidarhals(Vesturhals) and craters in the northern part are part of crater row in the north of Ridge Nupshlidarhals. Ogmundur is a male name in Iceland.  Located West of Lake Kleifarvatn. Drive road 427 and turn left on road 42 then park at Seltún and walk Preststígur. Walk estimated 2-3 hours up and down. 

Shelters made of rock, ancient paths and stacked walls. They have been discoverd near Eldvörp, a row of scoria and spatter cones formed in the Reykjanes Fires 1210-1240 AD. Location: Close to Eldvörp, walk from road 425.

High boulder ridge composed of well rounded stones.  The ridge is about 420 m long, 80 m wide and 10 m high. The rounded stones are 1-3 feet thick. Created by powerful storms, high waves and surf.  Located: On the tip of Reykjanes, next to cliff Valahnúkur. Take road 425.

VALAHNÚKUR MOUNTAIN Valahnúkur is composed of tuff layers, pillow lava and breccia. The mountain was formed in a single eruption and shows evidence of the different phases of the eruption. The tuff forms in explosive eruption, while the pillow lava forms when the lava erupts under water.   Tuff The mixture of lava rocks and hardened volcanic ash found in Valahnúkur is called tuff. Tuff forms when 1200°C hot lava rapidly cools in water. This forms glass fragments, as crystals do not have time to grow. The fragments quickly transform into tuff.   Breccia Lower down in Valahnúkur is a diagonal layer of breccia. Breccia forms when slag or ash form angled slopes. Individual pillows or parts thereof roll down the slope, are covered with ash and form the breccia layer.   Pillow lava Pillow lava is one of the most common lava types on Earth, as it is the most common lava that erupts from the oceanic crust. These strange pillows form in eruptions under water or under glaciers. Such eruptions are often where the pressure is too high to allow steam explosions to occur. They can also form when there is little or no gas in magma that rapidly pushes out from flowing lava. A glassy coating forms over the pillows as the magma cools rapidly. They are often several metres in length but only 10–30 cm in diameter. When examining a cliff wall with a cross-section of such lava, each bulbous formation looks like a ball or a pillow. The pillow lava in Valahnúkur probably formed in a sub-glacial eruption.

Ruins of the old farms Bali and Vigdísarvellir. Camping site sorrounded by beautiful scenery.  Location: Road 428 closed on winter time. 

A free standing, hyaloclastite mountain north of Grindavik. It offers great panoramic view over most of the Reykjanes Peninsula on fine days. The northeastern part of the mountain depicts thermal activity an to its north and northeast is an extensive high temperature area. It is split by a fissure called "The Thieves´ Gap" (Thjofagja), occupied by 15 thieves according to the legend. They were eventually overwhelmed and killed by trickery.

During the 19th century ships started frequenting this harbour again.  The merchants of Keflavik often unloaded salt, timber and heavy merchandize there and loaded fish from the farmers of Midnes and Hafnir.  In the beginning of the 20th century the arrivals of ships diminished, because of the opening of the Sandgerdi harbour and a new trading post there. Copy right: www.nat.is  Used by permission.

Thrainsskjoldur is an extensive lava mound north of Mt Fagradalsfjall. There are no resent remains of volcanic activity on its top, but vast lava areas around it suggest great volcanic activity most of the way around it during the recent Holocene epochs. Among its products is the lava field surrounding Mt Keilir, the hills Keilisborn, and almost overrunning the former Mt Small Keilir. The communities of Vogar and Vatnsleysustrond are located on top of the lava field of the craters around the Thrainsskjöldur Shield Volcano, which was one of the most active and productive volcanoes of the Reykjanes Area.

A lava flow formed in an eruption in the year 1151 AD. In that year a 25 km long fissure opened obliquely acorss the Reykjanes peninsula. The lava field is located in south of ridge Nupshlidarhals(Vesturhals) and craters in the northern part are part of crater row in the north of Ridge Nupshlidarhals. Ogmundur is a male name in Iceland.