Lake Kleifarvatn is the largest lake on Reykjanes Peninsula, which is a part of the Reykjanesfˇlkvangur Nature Reserve, established in 1975 and is a popular recreational fishing ground where people take their fishing poles for a relaxing day by the lake and also for scuba divers, exploring the underwater geothermal springs. The lake is about 10 square kilometers and one of Iceland's deepest lakes with the deepest part reaching 97 meters. It fills a depression at the foot of a steep mountain in a rather desolate but beautiful landscape. According to folklore, the lake is supposed to be a home of a worm like monster the size of a whale. An interesting fact is that the lake has no visible inlet and outlet of the lake, like most lakes. The reason is that most of the water flows underground. After a big earthquake in the year 2000, a fissure opened at the bottom of the lake and it slowly started to drain and lost 20% of its surface and got nicknamed the Disappearing Lake. However, in a few years time, sediments filled up the fissure, the leak stopped and the lake has now restored its previous surface area. Lake Kleifarvatn is popular with divers.
Close to the lake, you will also find the explosion crater GrŠnavatn (Green Lake) but the green color stems from geothermal algae present in the water. The high temperature geothermal area Selt˙n and KrřsuvÝk, with its many mudpools and fumaroles is also close to Lake Kleifarvatn. KrÝsuvÝkurbjarg is a seacliff with a rich birdlife in summer, located on the shore of the Reykjanes Peninsula, a short distance to the southwest from Lake Kleifarvatn. The detour off road 427 is about 3 kilometers and is a rough and bumpy gravel road, only suitable for a 4 wheel drive vehicle. The drive along the lakeshore of Lake Kleifarvatn is very scenic and offers many great photo opportunities. Travel options to Kleifarvatn can be seen at www.icelandroadtrip.com