Dead Wash Valley in Petrified Forest National Park, Arizona, United States of America

Dead Wash Valley in Petrified Forest National Park, Arizona, United States of America

Red hills of bentonite clay overlooking Dead Wash in Petrified Forest National Park, Arizona, United States of America

Red hills of bentonite clay overlooking Dead Wash in Petrified Forest National Park, Arizona, United States of America

Rock details near Marwick Head, Mainland, Orkney Islands, Scotland, United Kingdom, Europe

A view of Margerie Glacier against the Fairweather Range in Glacier Bay National Park and Preserve, UNESCO World Heritage Site, Alaska, United States of America, North America

Ice in all of its myriad forms in the Svalbard Archipelago, Norway, Arctic, Europe

A view of Swift Bay as seen from a commercial helicopter, Kimberley, Western Australia, Australia, Pacific

Aerial of a glacier, Kulusuk, Greenland, Denmark, Polar Regions

Views of Fortuna Bay on the northern coast of South Georgia, Southern Ocean, Polar Regions

Canyon country and bend of Colorado River, Dead Horse Point, Dead Horse Point State Park, Utah, United States of America, North America

Bend of Colorado River at Dead Horse Point at sunrise, Dead Horse Point State Park, Utah, United States of America, North America

Bend of Colorado River at Dead Horse Point at sunrise, Dead Horse Point State Park, Utah, United States of America, North America

Rock formations, Sarakiniko, Milos Island, Cyclades Islands, Greek Islands, Greece, Europe

View across wooded landscape to the Roccia dell'Orso (Bear Rock), evening, Capo d'Orso, Palau, Sassari, Sardinia, Italy, Mediterranean, Europe

A view of Tarr Inlet in Glacier Bay National Park and Preserve, UNESCO World Heritage Site, Southeast Alaska, United States of America, North America

Views of Austfonna, an ice cap located on Nordaustlandet in the Svalbard archipelago in Norway, Arctic, Europe

Unusual window formation in iceberg showing Booth Island in the background on the western side of the Antarctic Peninsula, Antarctica, Polar Regions

Cycads, a dioecious tree belonging to the order Cycadales found on Bigge Island, Kimberley, Western Australia, Australia, Pacific

A view of Johns Hopkins Glacier against the Fairweather Range in Glacier Bay National Park and Preserve, UNESCO World Heritage Site, Alaska, United States of America, North America

Huge granite rocks forming shoreline of the Strait of Bonifacio, Capo Testa, Santa Teresa di Gallura, Sassari, Sardinia, Italy, Mediterranean, Europe

Trail leading through valley to Rainbow Mountain, Uchullujllo, Pitumarca District, Canchis Province, Cuzco Region, Peru, South America

Slopes of the Quiraing, a geological wonder, its distinctive features resulting from landslips of basalt lavas upon softer sedimentary rocks beneath, northeast coast of Trotternish Peninsula, Isle of Skye, Inner Hebrides, Scotland, United Kingdom, Europe

Slopes of the Quiraing, a geological wonder, its distinctive features resulting from landslips of basalt lavas upon softer sedimentary rocks beneath, northeast coast of Trotternish Peninsula, Isle of Skye, Inner Hebrides, Scotland, United Kingdom, Europe

Streaky bacon limestone solution feature, Minchin Hole, Southgate, Gower, West Glamorgan, Wales, UK, Europe

Strokkur geyser erupting, in the Geysir hot springs area, Haukadalur geothermal area, Southwest Iceland

Strokkur geyser erupting, in the Geysir hot springs area, Haukadalur geothermal area, Southwest Iceland

Gran Cenote de Tulum in Yucatan Peninsula, Quintana Roo, Mexico. There are thousands of cenotes dotted all over Mexico���s Yucatan Peninsula, and their existence is as much a defining characteristic of the region as is the distinct geological feature from which they result. Once revered by the ancient Mayans as sacred wells, they are now magnets for tourists, adventurers, and explorers alike.

Moeraki Boulders, geological feature, round rock balls, washed by the waves of the surf at high tide, Coastal Otago, Moeraki, South Island, New Zealand, Oceania

Moeraki Boulders, geological feature, round rock balls, washed by the waves of the surf at high tide, Coastal Otago, Moeraki, South Island, New Zealand, Oceania

Moeraki Boulders, geological feature, round rock balls, some fragments lying broken in ruins on the beach, Coastal Otago, Moeraki, South Island, New Zealand, Oceania

Moeraki Boulders, geological feature, round rock balls, some fragments lying broken in ruins on the beach, Coastal Otago, Moeraki, South Island, New Zealand, Oceania