Twin polar bear cubs asleep in a snow den in Wapusk National Park, Manitoba (© AF archive/Alamy)

Spirit Island during winter season, Maligne Lake, Jasper National Park, Alberta (© Natapong Supalertsophon/Getty Images)

Marmot with the peak of Grossglockner in the background, Austria (© SeppFriedhuber/Getty Images)

Colossal limestone statues on Mount Nemrut, Adıyaman, Turkey (© Peerakit JIrachetthakun/Getty Images)

Northern Vosges Regional Nature Park, France (© Michel Rauch/Minden Pictures)

Sandstone formation and pools of water in 'The Wave,' Paria Canyon-Vermilion Cliffs National Monument, Arizona (© Dennis Frates/Alamy)

Mount Sefton in Aoraki/Mount Cook National Park, South Island, New Zealand (© AWL Images/Danita Delimont)

Great grey owls in Montreal (© rollandgelly/Getty Images)

Winter Skyline featuring the Château Frontenac tower, Quebec City (© NicolasMcComber/Getty Images)

Moon dog photographed at Hug Point Falls on the Oregon coast (© Ben Coffman/Tandem Stills + Motion)

Nieve penitente ice formations seen on Agua Negra Pass in the Coquimbo Region of the Andes, Chile (© Art Wolfe/Danita Delimont)

Almond blossoms surround a red barn in California's Central Valley (© Jeffrey Lewis/Tandem Stills + Motion)

Muskox with newborn in the central Arctic coastal plain of Alaska (© Steven Kazlowski/Danita Delimont)

Canada Jay (Perisoreus canadensis) in light snowfall, Ontario (© Alan Murphy/Minden Pictures)

Ocean waves crashing over a heart-shaped rock island off the coast of Sydney, Australia (© Kristian Bell/Getty Images)

Ski lifts in Whistler, B.C. (© Ben Girardi/Cavan Images)

Flowers and ironwork fence in front of a house in New Orleans, Louisiana (© Lauren Mitchell/Offset by Shutterstock)

Perito Moreno Glacier in Patagonia's Los Glaciares National Park, Argentina (© Juergen Schonnop/Getty Images)

Stones in a river near the hamlet of Lavertezzo, in the Valle Verzasca of Switzerland (© Robert Seitz/Offset by Shutterstock)

Parrotfish off the coast of the Negros Oriental province in the Philippines (© Tim Fitzharris/Minden Pictures)

Clearing snowstorm, Yosemite National Park, California (© Jeff Lewis/Tandem Stills + Motion)

Porto, Portugal (© Kanuman/Shutterstock)

The Cobb breakwater, Lyme Regis, Dorset, England (© Ross Hoddinott/Offset by Shutterstock)

Dalmatian pelicans on ice, Lake Kerkini, Greece (© Guy Edwardes/Minden Pictures)

Le Morne Brabant, Mauritius (© Hemis/Alamy)

Trevi, Umbria, Italy, with almond flowers in the foreground (© Maurizio Rellini/eStock Photo)

Red lanterns hanging in Jinli Street, Chengdu, China (© Philippe LEJEANVRE/Getty Images)

Traditional farmhouses at Skaftafell, Vatnajökull National Park, Iceland (© Jarcosa/Getty Images)