Nature Conservation
Lake Myvatn and River Laxa have been protected by law since 1974. The objective of the law is to protect the landscape, geological formations and wildlife of Lake Myvatn and the river Laxa and to promote research for this purpose.

River Laxa
The protected area covers the entire district of Skutustadahreppur and the river Laxa, as well as the islets and tributaries of the river and a 200-metre wide stretch of riverbank along the river reaching all the way to Skjalfandi Bay.

Lake Myvatn and the river Laxa are listed as internationally important wetlands according to the Ramsar Convention. The Nature Conservation Agency is responsible for the surveillance of the area and ensures that its ecology is not disturbed. Wardens operate in the Myvatn district, providing assistance, information and guidance on organized hikes. Further information about the nature of Myvatn can be obtained at the Reykjahlid Visitor Centre. Tourists are requested to treat the area's delicate nature with care and avoid causing disturbance to wildlife.

Lake Myvatn
Lake Myvatn's area is about 37 square kilometres. Numerous bays and creeks incise its coastline and the lake comprises some fifty islands and islets. The lake is not very deep, its average depth being 2.5 metres, and the maximum depth is 4 metres. The ecosystem of Lake Myvatn is unique. The lake derives its name from the profusion of midges that pervade the area. Bird life is extremely diverse and more species of duck are believed to live around Lake Myvatn than anywhere else in the world. The natural environment of the area is very diverse and the landscape has a unique character, being formed by volcanic activity.

Geology
Iceland lies on the boundary of two tectonic plates, the North American and the Eurasian plates. Those plates move apart at a rate of about 2 centimetres a year. Volcanic lava wells up between them and fills up the rift. The volcanic zone, to which the Lake Myvatn region belongs, lies on the boundary of those two tectonic plates, and volcanic activity in the area is considerable.

Mt. Hverfjall
Mt. Hverfjall is a gigantic tephra crater, which erupted 2,500 years ago. The crater is one kilometre in diameter and 140 metres deep. Tephra has been carried from Hverfjall, all over the Myvatn district. A landslide apparently occurred in the south part of the crater during the eruption, which accounts for the disruption of the round shape of the mountain. During the Age of Settlement, lava flowed from Svortuborgir, at the southern end of Namafjall Mountain, around Mt. Hverfjall, which was nearly encircled by the lava. At the same time an eruption occurred in the slopes above the valley of Hlidardalur.

The Younger Laxa Lava Field
About two centuries after the eruption of Mt. Hverfjall a great eruption occurred in a 12-kilometre long fissure south of the mountain. The resulting lava field has been given the name Younger Laxa Lava Field. The Older Laxa Lava Field under it is about 3,800 years old. A great row of craters, Ludentsborgir, was formed on the fissure.

The Younger Laxa Lava Field inundated most of the Lake Myvatn area, covered and destroyed a large lake. The lava flowed on down the River Laxa Valley, reaching the sea in the north. Wherever the flowing lava overran lakes, bogs and marshlands, water was trapped underneath and steam explosions created false craters in many places. They are named pseudocraters. There are clusters of beautiful pseudocraters all around Lake Myvatn, in the Laxa Valley and Adal Valley. Some of the craters have been eroded by water, leaving black pumice slides exposed. Many of the craters are double and some even triple. The largest pseudocraters can be found near Mt. Vindbelgur.

Dimmuborgir
Dimmuborgir are peculiar lava formations in the Younger Laxa Lava Field. A pool of molten lava, about 2 kilometres in diameter, was formed there during the fissure eruption of Ludentsborgir. This pool was drained when the lava exited towards Lake Myvatn, leaving behind high pillars of lava, which have taken on most bizarre forms. It is believed that these pillars were formed in the pool where steam percolated through the molten lava and cooled it. Horizontal lines, formed when the half-congealed lava crust of the pool gradually collapsed, are a frequent sight in the lava. The collapsing crust also coated the pillars with scoria, which can be seen in many places as a thin coating with vertical etchings. Lava formations like Dimmuborgir have been found at the bottom of the ocean off the coast of Mexico but are not known to exist on dry land outside the Lake Myvatn region. The lava pillars at Hofdi (named Klasar and Stripar) are similar formations.

The Krafla Fires (1975-1984) and the Myvatn Fires (1724-1729)
The area around Mt. Leirhnjukur is in fact a central volcano. About one hundred thousand years ago, this was the site of a volcanic cone that emitted great volumes of ash and then subsided. The caldera thus formed has now filled with later volcanic material, so the landscape looks flat. Underneath, however, there is a magma chamber at a depth of about 3 kilometres.

Volcanic activity in Krafla is periodic. The magma chamber expands by force of lava issuing from below, which raises the ground. The magma chamber then suddenly bursts and lava flows northwards or southwards through underground fissures as the crust of the earth rifts. Part of the magma may be forced to the surface in the form of an eruption. As the pressure in the magma chamber decreases, the ground subsides quickly. This process repeats itself at a few months' interval for a few years running.

Eruptions began in 1724 in the Lake Myvatn area with a violent explosion, which created the crater Viti (The Inferno). A series of earthquakes and eruptions occurred in the following years in the vicinity of Mt. Krafla. The greatest eruption occurred in 1729 when lava ran from Mt. Leirhnjukur all the way down to Lake Myvatn. During the eruption, the lava ran around the church at Reykjahlid, which survived. After a dormant period of 250 years, a new series of volcanic eruptions ensued in the area around Mt. Krafla. These were the Krafla fires (1975–1984).

Flora and Fauna at Lake Myvatn and River Laxa
Lake Myvatn was created when the Younger Laxa Lava Field blocked a river course extending into the Laxa Valley about 2,300 years ago. Precipitation water permeates quickly into the bedrock in the volcanic area and emerges as spring water at its edges. About 35 cubic metres of water flow every second from a myriad of warm and cold springs on the lake's east bank and from Lake Graenavatn. The water is rich in minerals and is one of the main reasons for the fertility of Lake Myvatn. A vast variety of algae grows in the lake, providing sustenance for midge larvae and crabs, both of which are important food for birds and fishes. Lake Myvatn is sufficiently large and its renewal of water sufficiently slow for its ecosystem to flourish despite its altitude of 277 metres above sea level. Vegetation on the bottom of the lake is ample and the conditions for waterfowl are favourable, as the water is suitably shallow. An abundance of midge larvae thrive on the bottom of the lake, transforming into pupae and growing into full-sized midges, particularly in the beginning of July and August.

River Laxa discharges Lake Myvatn in three channels, Yztakvisl, Midkvisl and Sydstakvisl. The river flows in small cascades between islets grown with wood crane's bill, angelica, buttercups and willow. The river is home to the Barrow's Goldeneye and Harlequin Ducks, and the trout fishing in River Laxa ranks among the best in the world. The water in Lake Myvatn often takes on a greenish or brownish tinge in the summertime because of the blue-green algae (Cyanophyta) that inhabit the lake. The algae are carried into River Laxa and form the basis of its food chain. River Laxa is the most fertile river in Iceland. Black fly larvae constitute the river's most important food for fish and fowl. The female black flies distract blood from livestock and people to gain nourishment for breeding.

Agriculture and Other Industries
Sheep farming has been the most important industry in the Lake Myvatn area for centuries. Hay was obtained from the islands, lake banks and wetlands, and each hayfield was small. Hay was transported by sleighs to the farms in the wintertime. The remains of huts and out-lying sheep cots can be seen in many places. Sulphur was processed for export from hot spring areas, such as Mt. Namafjall and Fremrinamur.

The exploitation of natural resources in the area has a long history. Trout and Char fishing has been practiced for centuries. Eggs are collected regularly from the most common duck species every spring.

In 1967, a diatomite (kieselguhr) plant was built at Bjarnarflag, where diatomaceous deposits pumped up from the bottom of Lake Myvatn are dried using geothermal steam. The Krafla power plant, built in 1974-1976, exploits geothermal activity to produce electricity. The Lake Myvatn region is one of the chief tourist attractions in Iceland and provides various tourism-related services. Accommodation is available in hotels, at various farms or at designated campsites. There are also restaurants and grocery stores in the area.

Archaeology and Folklore
Two widely known archaeological finds are connected with the Lake Myvatn area. Boards, counters and dice from a Viking board game were found in a grave near Baldursheimur in 1860. At the farm Hofsstadir, the remains of a dwelling lodge from the 11th century were discovered in 1908. The lodge was originally 45 metres in length. Of local ancient heroes, Viga-Skuta is the most renowned. His feats are recounted in the Reykdaela Saga and Viga-Glum's Saga. Viga-Skuta possessed a battle-axe named Fluga, with which he slew many men. The ogress Kraka lived in the Blahvammur cave on the side of Mt. Blafjall. She created the river Kraka to wreak revenge upon the inhabitants of the area. Another ogress lived at Skessuhali. She was petrified by the rising sun as she was returning from Lake Myvatn on her boat, and can still be seen sitting on the rock Nokkvinn (the barge), located south of Mt. Hverfjall. The most renowned local ghost is Myvatnsskotta, a great cause of evil.

Environmental Issues
The main environmental issues of the Lake Myvatn area are connected with the processing of minerals and energy, as well as the erosion of soil. Plans for large-scale power plants in the river Laxa, led to the Laxa river dispute around 1970 and the subsequent legal protection of the area. A nature research centre was established in the aftermath. Diatomite mining disrupts the conditions for life in the lake. The Krafla geothermal power plant has a noticeable impact on the landscape. Cinder mining spoils the appearance of some of the craters in the area, most notably in the Jardbadsholar hills. A great deal of erosion is in progress east of Lake Myvatn, and the vegetation and landscape of Dimmuborgir were threatened for some time by advancing sand dunes. Organized soil cultivation is under way in order to stop the sand deposits.

Dear Visitor
Lava formations and moss covers soon lose their appeal if they are broken or trampled on.
The avifauna is sensitive to interruption.
Never litter, and help us keep the area clean.
Off-road driving is prohibited.
Recreational vehicles and camping are permitted only in designated areas.
Nature, with its diversity of life and landscapes, must be treated with respect.
The locals should also be approached with consideration. 
Please be extremely careful in geothermal areas and enjoy your stay.