Ice cave in the Skaftafell National Park in Iceland. Ice caves collapse and new ones form as each glacier grinds slowly towards the sea. Local guides can help you (without dying) find one. (Visit Skaftafell National Park in Iceland.
Photographing the Jaw-Dropping 'Crystal Caves' of Iceland
Lake Superior Ice Caves on Grand Island, just off the shore in Munising, Michigan. A short walk from Sand Point Beach across frozen Lake Superior will leave you at the base of ice curtains more than 30 feet tall and stretching hundreds of feet wide.