Lake Kleifarvatn, situated on the Reykjanes Peninsula in Iceland, is a captivating volcanic lake renowned for its serene beauty and geological significance. Spanning an area of approximately 8 square kilometers (3 square miles), Kleifarvatn is one of Iceland's largest lakes and is surrounded by stark, volcanic landscapes.

The lake is notable for its deep blue waters, which contrast strikingly with the black basalt shores and surrounding lava fields. Fed primarily by groundwater and precipitation, Kleifarvatn has no visible surface drainage, a feature unique among Icelandic lakes.

Kleifarvatn's volcanic origins are evident in the geothermal activity along its shores, including hot springs and mud pots that create surreal landscapes. The lake's surroundings are also rich in geological formations, with occasional steam vents and bubbling mud pools dotting the area.