Kerid Crater Lake, Iceland

This is a 55 m deep explosion crater Kerid that harbours a small green lake in the Grímsnes region. It is now filled with water, creating a lake whose steep circular slopes resemble an ancient amphitheatre. The crater is nearly 3000 years old, and is a part of a group of volcanic hills called Tjarnarhólar. It is a popular sight to visit for tourists, often displaying intense colors.