Steps from the dramatic geothermal area at Krýsuvík Seltún lies the sweeping blue expanse of Kleifarvatn Lake. Nestled below a steep mountain, the seemingly deserted space is an attractive spot for a quiet walk. A small path circles the lake, jogging around water's edge and over small black lava rocks. Not only is this picturesque lake the largest on the Reykjanes Peninsula, it is also said to be inhabited by a monster. The serpent-like creature, the size of a large whale, has been spotted surfacing for two-minute intervals.
Another unique feature of this incredibly deep lake (97 m – 318 feet -- at its deepest point) is that it has no visible surface drainage, meaning no rivers run to or from it. Because of this, the water level only changes with the ground water, which has varied almost 4 metres (13 feet) in a few decades. After the earthquake of 2000, a fissure formed below the lake and it started to drain quickly. But the fissure has since refilled and the lake has returned to its previous levels. Today, Kleifarvatn Lake is an attraction for walkers, hikers, birdwatchers, and fishermen seeking the trout that thrive in its waters.
For those who wish to explore the area on foot, the Hafnarfjörður Tourist Information Centre offers a detailed map of the Krýsuvík area, showing hiking and walking routes and describing the local history, geology, folklore, and sightseeing attractions.
On a short trip to Iceland? One of the best one-day itineraries is a visit to the Krýsuvík geothermal area, the Krýsuvík Cliffs, the Kleifarvatn Lake, and finally a stop at the Blue Lagoon. This “all-of-Iceland-in-a-day” tour is varied, vast, and sure to impress.
Also of note: if the eerie and scary monsters of Kleifarvatn Lake appeal, you may be interested in the crime novel Kleifarvatn (in English: The Draining Lake) by best-selling author Arnaldur Indriðason.