Jeff Foott / Hiker near waterfall and rainbow, Nevada Fall, Yosemite National Park, California

Suzi Eszterhas / African Elephant (Loxodonta africana) in defensive posture towards safari vehicle, Sabi Sands Private Game Reserve, South Africa

Yva Momatiuk & John Eastcott / Ice climber scaling Skaftafellsjokull Glacier, Skaftafell National Park, Iceland

Yva Momatiuk & John Eastcott / Ice climbers atop Skaftafellsjokull Glacier, Skaftafell National Park, Iceland

Yva Momatiuk & John Eastcott / Ice climber scaling Skaftafellsjokull Glacier, Skaftafell National Park, Iceland

Jordi Chias / Woman snorkeller swimming inside lagoon Toau atoll, Tuamotu Archipelago, French Polynesia, Pacific Ocean.

Matthias Breiter / Tourist and icebergs, Ilulissat, Greenland

Colin Monteath/ Hedgehog House / Kayakers paddling back to cruise ship Polar Pioneer, Lemaire Channel, Antarctic Peninsula, Antarctica

Pascal Tordeux / Aerial view of Cappadocia with hot air balloon, Turkey, March 2006.

Pete Oxford / Yellow-tailed Surgeonfish (Prionurus laticlavius) school and snorkeler, Galapagos Islands, Ecuador

Pete Oxford / Yellow-tailed Surgeonfish (Prionurus laticlavius) school and snorkelers, Galapagos Islands, Ecuador

Pete Oxford / Red-footed Booby (Sula sula) flying juvenile being photographed by tourist, Genovesa Island, Galapagos Islands, Ecuador