Ice, ice, caving

The Land of Fire and Ice is home to countless natural wonders, like this brilliant blue cave formed within the ice of a glacier. (Glacier caves are often called ice caves, but the term 'ice cave' is properly used to describe a bedrock cave that contains year-round ice; a glacier cave is formed entirely within the ice of a glacier.) The majority of Iceland's glacier caves are in Vatnajökull glacier, which covers about 8% of the island nation and is one of the largest glaciers in Europe.
© Marco Bottigelli/Getty Images