Aurora borealis over Sycamore Gap, Hadrian's Wall, Northumberland, England (© Guy Edwardes/NPL/Minden Pictures)

Bengal tiger, Ranthambore National Park, Rajasthan, India (© eROMAZe/E+/Getty Images)

Alpine marmot, High Tauern National Park, Austria (© Misja Smits/Minden Pictures)

Corjuem Fort in Goa, India (© Ingvar Kuznetsov/Shutterstock)

Speloncato, Corsica, France (© Jon Ingall/Alamy)

Monarch butterflies, Monarch Butterfly Biosphere Reserve, Angangueo, Mexico (© Sylvain Cordier/Minden Pictures)

Oymyakon, Russia (© Alexandr Berdicevschi/Getty Images)

Ice sculpture, Ottawa, Canada (© S. Garcia Cournoyer/Alamy)

Treetop Walk Saarschleife, Orscholz, Mettlach, Germany (© Hans-Peter Merten/Huber/eStock Photo)

Seven Sisters cliffs, East Sussex, England (© Paul Daniels/Alamy)

Old Town, Bern, Switzerland (© Xantana/Getty Images)

Tea plantations, Munnar, Kerala, India (© SvitlanaBelinska/iStock/Getty Images Plus)

Darwin's Arch, Galápagos, Ecuador (© miralex/Getty Images)

American bison, Yellowstone National Park, Wyoming, USA (© Gerald Corsi/Getty Images)

Heart-shaped island, Indian Ocean, Maldives (© Willyam Bradberry/Shutterstock)

Red lanterns, Chengdu, Sichuan, China (© Philippe Lejeanvre/Getty Images)

Cranborne Chase, Dorset, England (© Guy Edwardes/Minden Pictures)

Red deer, Richmond Park, London, England (© Ian Schofield Images/Offset/Shutterstock)

Great tits, France (© Eric Ferry/Alamy)

Berchtesgaden Alps, Bavaria, Germany (© Spotcatch/Westend61/Offset)

Humpback whales and dolphins, Hawaii, USA (© drewsulockcreations/Getty Images)

Bactrian camels, Kazakhstan (© Nurlan Kulcha/Alamy)

Cypress tree tunnel, Point Reyes National Seashore, California, USA (© Spondylolithesis/Getty Images)

Vatnajökull, Iceland (© Marco Bottigelli/Getty Images)

Wheaton River near Whitehorse, Yukon, Canada (© Robert Postma/Design Pics)

Lamplugh Glacier, Glacier Bay National Park, Alaska, USA (© Andrew Peacock/Getty Images)

Polar bears, Wapusk National Park, Manitoba, Canada (© Andre Gilden/Minden Pictures)

Cotswolds, England (© Peter Adams/Getty Images)