Kleifarvatn Lake

Kleifarvatn Lake is among the most popular dive sites in Iceland. You can dive in a geothermal spring at Kleifarvatn Lake, 30 minutes south of Reykjavik. The drive to the lake is spectacular, past black, volcanic rocks that will make you think you’re on the moon. The dive is no different. On walking into the water, you follow a line on the lakebed to a cratered area no deeper than 33 feet (10 m). You will see continuous streams of bubbles all around you and smell a mixture of sulfur and hydrogen sulfide gases. The lakebed here has a very clay-like consistency. It looks scorched as though the gases being released used to be much hotter.

There are a few deep craters with overhanging walls and bubbles coming up from the darkness. All over the lakebed, you are also likely to see numerous dead brown trout, which makes for a very eerie experience. And just when you thought it couldn’t get any weirder, the movement of gas bubbles coming up through the lakebed causes the surrounding rocks to vibrate, which you’ll be able to feel. Tip: take an egg with you to hard boil underwater. In the summer the lake can be as warm as 57 F (14 C) but you should still dive in a drysuit. It’s a very easy dive so open-water certification is adequate. The lake freezes over in winter, so unless you’re an ice diver, visit from May to October.

Location: Reykjanes, Iceland