Iceland formed long ago by volcanoes, is known for its otherworldly landscape, with steaming fields and percolating mud. The volcanic activity produces naturally heated water, which Icelanders have cleverly harnessed not just as an energy source, but for thermal baths and pools. Geothermal experiences - both visual and immersive - are worth seeking out on a visit here.
Wandering through the colorful terrain of a geothermal field is a classic Icelandic treat. The most visited geothermal sight is Geysir, home to the world's first-known geyser, on Iceland's most famous tourist route, the Golden Circle. The original Geysir is now mostly dormant, but the field around it still steams and bubbles nonstop, periodically punctuated by a dramatic eruption of scalding water from the one predictably active geyser, Strokkur. Stokkur erupts about every five minutes, shooting about 50 feet into the air.