On the southern part of the Reykjanes peninsula lies Lake Kleifarvatn, a starkly beautiful body of water with black sand beaches. Both large and deep, it exudes an eerie atmosphere with barren, volcanic surroundings. 

The lake is the largest one on the Reykjanes peninsula. It’s almost 100 meters (328 feet) deep, and there are many picturesque places around it. One of the best views is from Lambstangi spit on the lake’s southern end.  People can enjoy arctic char fishing during the summer months.  When you visit the area, be on the lookout for the resident Kleifarvatn monster, a legendary worm-shaped aquatic beast the size of a whale swimming around the lake.

No springs or rivers feed Lake Kleifarvatn, nor is there a river or a creek going out from it. Most of its water enters and leaves via underground tunnels. The water level dropped after an earthquake in the year 2000, and though it had gained almost its original size in 2008, the lake seems to be receding again.

Kleifarvatn in literature

The lake plays a pivotal role in a novel by one of Arnaldur Indridason, Iceland’s one of Iceland’s most popular crime fiction novelists. In English the novel title is The Draining Lake. In the novel the lake’s natural draining reveals a dead body and the fictional detective Erlendur must solve the mystery.