Heart-shaped island with sandy beach, offshore coral reef, Indian Ocean, Maldives (© Willyam Bradberry/Shutterstock)

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

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

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

Big Air Shougang venue in Shijingshan District, Beijing, China (© Gao Zehong/VCG via Getty Images)

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

Winter in Oymyakon, Russia (© Alexandr Berdicevschi/Getty Images)

Ice sculptures from the 2013 edition of Winterlude in Ottawa (© S. Garcia Cournoyer/Alamy)

Rock art near Santa Fe, New Mexico (© Scott Warren/Cavan)

Granville Island marina in Vancouver (© Albert Pego/Shutterstock)

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

Tea plantations in the mountains of Munnar in Kerala, India (© SvitlanaBelinska/iStock/Getty Images Plus)

Darwin's Arch with Darwin Island in background, Galápagos, Ecuador (© miralex/Getty Images)

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

Red lanterns hanging on trees during the Lantern Festival in Chengdu, Sichuan, China (© Philippe Lejeanvre/Getty Images)

Beech woodland in hoar frost, Cranborne Chase, Dorset, England (© Guy Edwardes/Minden Pictures)

Flamenco dancers outside Palma de Majorca, Spain (© Torleif Svensson/Getty Images)

Great tits on a branch during winter in France (© Eric Ferry/Alamy)

A frozen lake in Banff National Park (© RuslanKaln/Getty Images)

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

Northern Lights over open water in winter near Whitehorse, Yukon (© plainpicture/Design Pics/John Hyde)

Two Bactrian camels in Kazakhstan for Twosday (© Nurlan Kulcha/Alamy)

The cypress tunnel at Point Reyes National Seashore in California (© Spondylolithesis/Getty Images)

Flowing river inside a glacier cave, Vatnajökull, Iceland (© Marco Bottigelli/Getty Images)

Sunset over the Wheaton River as the light hits Grey Ridge near Whitehorse, Yukon (© Robert Postma/Design Pics)

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

Polar bear mother with cubs in Wapusk National Park, Manitoba (© Andre Gilden/Minden Pictures)

Hoar frost and snow in the Cotswolds, England (© Peter Adams/Getty Images)