The Krafla Viti Crater in Iceland is a must-see spot near Lake Myvatn, known for its stunning blue water and colorful mountains. The crater was formed during a volcanic eruption in 1724 and is surrounded by a geothermal area. Visitors can take a one-hour rim walk around the crater, but swimming is not allowed. The area can be slippery, especially in winter, so caution is advised. Accessible by car, it's a surreal and post-apocalyptic landscape that will leave you in awe.