Krafla Viti is a volcanic crater lake located in the Krafla volcanic area in northeast Iceland. The crater was formed during an eruption in 1724, and its name "Viti" means "hell" in Icelandic due to the red color of the water, which is caused by the presence of sulfur.
The surrounding landscape is also stunning, with volcanic rock formations and geothermal vents. You can hike around the crater rim for panoramic views of the area, or even take a dip in the nearby geothermal hot springs. It's a unique and otherworldly experience that shouldn't be missed if you're interested in Iceland's natural wonders.