Kleifarvatn
Kleifarvatn is the largest lake on the Reykjanes Peninsula, situated between Sveifluháls and Vatnshlíð. It is the third-largest lake in South Iceland (10 km²) and one of the country's deepest (97 m). The lake is very beautiful and a popular tourist destination, and ideal to visit on a tour of the area. Krysuvík.
The water has little inflow but no above-ground outflow. The water level fluctuates by up to 4 metres over decades, which was considered great. secret but it follows the area's groundwater surface. There is considerable geothermal heat in the south of the lake and also off Inner Stack, to its west. After the earthquake in 2000, the lake began to shrink and has decreased by 20% since then.
Members of the Hafnarfjörður Angling Club introduced trout fry into Kleifarvatn around 1960, and the fish are thriving in the lake. It is now a thriving fishery. Game lake with large brown trout and good-sized grayling. The best fishing spot is at the southern end of the lake, where hot groundwater from geothermal areas seeps into it.
In the past, people claimed to have seen worm-like monsters in the water, black in colour and about the size of a large whale.
A famous novel is named after the lake, Kleifarvatn, the eighth novel by Arnaldur Indriðason, one of Iceland's most popular crime writers. The novel is about, among other things, a skeleton that was found in the lake when its level dropped following an earthquake.