Dean's Blue Hole, Long Island, Bahamas.

Gothic Pass near Crested Butte, CO

Peak Lake, Somiedo Natural Park, Spain

Matterhorn Mountain, Switzerland

CRYSTAL CAVE Svínafellsjökull Skaftafell, Iceland

Darvaza gas crater, Turkmenistan

Valley in Iceland

Jewel Cave, Augusta, WA, Australia

Old Man's Cave - Hocking Hills, Ohio

Reed Flute Cave, China

Ocqueoc River, Presque Isle County, Michigan

Mayon Volcano's Perfect Cone, Philippines

Los Roques, Venezuela