Camel caravan in the Tibesti Mountains, Chad

Camel caravan in the Tibesti Mountains, Chad

Four-wheel drive crossing a river ford between Ouarzazate and Ait Ben Haddou, Ounila River valley, Ouarzazate Province, Draa-Tafilalet region, Morocco

Commercial ferries taking people and vehicles from one side to the other in Sognefjord, Norway

Hikers on path along levada (aqueduct) of Green Cauldron (Caldeirao Verde), Madeira island, Atlantic Ocean, Portugal

The remains of the camp where Fridtjof Nansen over-wintered with Hjalmar Johansen in 1895-96, Franz Josef Land, Russia, Arctic Ocean, Eurasia

Expedition tourists follow a marked route on Half Moon Island, view to Livingston Island, South Shetland Islands, Antarctica, Polar Regions

Animal pawprints in the snow in arctic landscape at Kvaløysletta, Kvaloya Island, Tromso in Arctic Circle Northern Norway

Animal pawprints in the snow in arctic landscape at Kvaløysletta, Kvaloya Island, Tromso in Arctic Circle Northern Norway

Alaskan Huskies dog-sledding at Villmarkssenter wilderness centre on Kvaloya Island, Tromso in Arctic Circle Northern Norway

Alaskan Huskies dog-sledding at Villmarkssenter wilderness centre on Kvaloya Island, Tromso in Arctic Circle, Northern Norway

Alaskan Huskies dog-sledding at Villmarkssenter wilderness centre on Kvaloya Island, Tromso in Arctic Circle, Northern Norway

Alaskan Huskies dog-sledding at Villmarkssenter wilderness centre on Kvaloya Island, Tromso in Arctic Circle Northern Norway

Alaskan Huskies dog-sledding at Villmarkssenter wilderness centre on Kvaloya Island, Tromso in Arctic Circle, Northern Norway

Alaskan Huskies dog-sledding at Villmarkssenter wilderness centre on Kvaloya Island, Tromso in Arctic Circle Northern Norway

Alaskan Huskies dog-sledding at Villmarkssenter wilderness centre on Kvaloya Island, Tromso in Arctic Circle, Northern Norway

Alaskan Huskies dog-sledding at Villmarkssenter wilderness centre on Kvaloya Island, Tromso in Arctic Circle Northern Norway

Alaskan Huskies dog-sledding at Villmarkssenter wilderness centre on Kvaloya Island, Tromso in Arctic Circle, Northern Norway

On the Trans-Amazonian Highway, Amazon region, Brazil

Shaun Norman, Antarctic Mountaineer, searches for a route across the Polar Plateau.

Eric Chabala looks for foot placement on an overhanging bouldering route. Eric is on a bouldering expedition in Patagonia, outside of El Chalten, Argentina. Fitz Roy Peak is in the background.

Biospheres Expedition, Low Tatra Mountains, Slovakia