One of the things you can find in the area of Myvatn Lake is an impressive and quite surreal lava foundation. Actually, lava foundations, as there's the field near the Krafla volcano with formations created during its 1984 eruption and the 18th century moss covered ones at the foot of Mt. Hverfjall.
Lake Myvatn area is a volcanic zone located on the boundary of two tectonic plates Iceland lies on. The plates steadily move apart, at a rate of about 2 cm a year, so volcanic activity in the area is considerable and thus it has become one of the main points of interest for anyone visiting this part of the world.
As we were walking away from Mt. Hverfjall, Antoine was telling me about this one time he was travelling with some friends and decided to sleep on one of the islands on a lake they were next to.