Arctic fox sleeping (© Chansak Joe/Getty Images)

Aerial view of Venice, Italy (© Clement Leonard/Getty Images)

Staubbach Falls at Lauterbrunnen, Canton of Bern, Switzerland (© pongnathee kluaythong/Getty Images)

A herd of impalas, Londolozi Game Reserve, South Africa (© Mint Images/Getty Images)

Nuuk, Greenland (© nevereverro/Getty Images)

Turret Arch framed by North Window in Arches National Park, Utah, United States (© Jim Patterson/TANDEM Stills + Motion)

Starling murmuration over the ruins of Brighton's West Pier, England (© Philip Reeve/Photodisc/Getty Images)

Giant redwood trees in Muir Woods National Monument, California, United States (© photo by canderson/Getty Images)

The Matterhorn reflected in Lake Stellisee at sunrise, Zermatt, Switzerland (© Andy Trowbridge/naturepl.com)

Blue walls of Chefchaouen, Morocco (© AnetteAndersen/Getty Images)

Eurasian otter and pup, Estonia (© Sven Zacek/naturepl.com)

Vale of Clwyd, Wales (© Valerie Blencowe/Getty Images)

The staircase of the Fortress of Palamidi, Nafplio, Greece (© George Pachantouris/Getty Images)

The fishing village of Reine, Norway (© Roberto Moiola/Cavan Images/SuperStock)

Leopard at Etosha National Park, Namibia (© Norbert Achtelik/Cavan Images)

Basilica of San Francesco di Paola, Naples, Italy (© javarman3/Getty Images)

White Sands National Park, New Mexico, United States (© Francesco Carucci/Getty Images)

Frozen Abraham Lake, Alberta (© Luis F Arevalo/Getty Images)

Gentoo penguin, Petermann Island, Antarctica (© Paul Souders/DanitaDelimont.com/Alamy)

Eurasian red squirrel (© Galina Jacyna/Getty Images)

Karlovy Vary, Bohemia, Czechia (© Henryk Sadura/Getty Images)

Sheep grazing in snow, Iceland (© Christophe Lehenaff/Getty Images)

Andermatt village in the Alps, Switzerland (© Xantana/Getty Images)

Burns National Heritage Park, Ayr, Ayrshire, Scotland (© Alister Firth/Alamy)

Neuschwanstein Castle, Bavaria, Germany (© www.fredconcha.com @ All Rights Reserved/Getty Images)

Dalmatian pelicans, Lake Kerkini, Greece (© Guy Edwardes/naturepl.com)

Whanganui National Park, Retaruke, New Zealand (© Matthew Micah Wright/Getty Images)

The eight-story open atrium of Milwaukee City Hall, Wisconsin, United States (© lavin photography/Getty Images)

'Kimono' sculpted by Hiroaki Kimura and Masaki Takahashi of Japan, Winterlude 2010 (© PensiveDragon/Shutterstock)

Plains zebras, Etosha National Park, Namibia (© Mogens Trolle/Shutterstock)