Lake Kleifarvatn is located in a geothermal area on the Reykjanes peninsula, near Krýsuvík hot spring area. Being situated right on the mid-Atlantic ridge the volcanic landscape does not only make up the lakes surroundings but also adds exceptional features to this diving spot. Kelifarvatn has underwater hot springs that pump warm water and gases into the lake, making it a totally outstanding diving site. Kleifarvatn is one of the deepest lakes in Iceland. The lake has no visible water coming in or going out of it as all this happens under surface. A large earthquake in 2001 caused the subsurface to change resulting in the lake diminishing greatly with up to 20% if it disappearing at some point. The cracks caused by the earthquake have since then gradually filled up and in 2008 the lake had reached its original size again. The bottom of lake Kleifarvatn consists of mud and sand and the spot is considered an excellent spot for inexperienced divers and was i.e. used for training for some time. Kleifarvatn has been connected with mystique over the years and was the main setting for one of Iceland’s most widely read crime novel that also takes its name from the lake.