Bear cubs playing by a lake (© Sergey Ivanov/Getty)

Emerald Lake near Carcross, Yukon, Canada (© David Noton Photography/Alamy Stock Photo)

Milky Way over the Bisti/De-Na-Zin Wilderness in New Mexico (© Cory Marshall/Tandem Stills + Motion)

A symmetrical forest known as a Nelder plot (© Rachid Dahnoun/Tandem Stills + Motion)

Qingming Bridge in Wuxi, China (© Hanyu Qiu/Shutterstock)

Male roe deer surrounded by heather (© wonderful-Earth.net/Alamy Stock Photo)

North American beaver swimming in Grand Teton National Park, Wyoming (© Charlie Hamilton James/Getty Images)

The National Wallace Monument, overlooking Stirling, Scotland (© Elena Korchenko/age fotostock)

Bioluminescent algae along the shores of the Matsu Islands off the coast of Taiwan (© Wan Ru Chen/Getty Images)

Lion cubs wrestling in Samburu National Reserve, Kenya (© Mark C. Ross/Getty Images)

Tulip fields in the Duin- en Bollenstreek region, Netherlands (© Frans Sellies/Getty Images)

The Mount Washington Observatory in New Hampshire (© Mike Theiss/Getty Images)

Forest with flowering plants, Beijing, China (© Raymond Shi/EyeEm/Getty Images)

Path to San Juan de Gaztelugatxe, Basque Country, Spain (© Anton Petrus/Moment/Getty Images)

石楠花丛中的雄狍 (© wonderful-Earth.net/Alamy Stock Photo)

Sacred lotus growing in water (© Tuan Nguyen Minh/Getty Images)

Hope Valley, Peak District, England (© Daniel_Kay/Getty Images Plus)

Tŵr Mawr Lighthouse on Llanddwyn Island in Anglesey, North Wales (© Jon Arnold/DanitaDelimont.com)

Paepalanthus flowers at sunset, Chapada dos Veadeiros National Park, Brazil (© Marcio Cabral/Getty Images)

Chipmunk storing food in its cheeks (© mlorenzphotography/Getty Images)

Laysan albatross chick on Midway Atoll, Hawaiian Leeward Islands (© Jaymi Heimbuch/Minden Pictures)

Casa Batlló, Barcelona, Spain (© Jon Arnold Images Ltd/Alamy)

Quinault Rainforest in Olympic National Park, Washington (© Jason Savage/Tandem Stills + Motion)

Ice cave at sunset in Vatnajökull National Park, Iceland (© Johnathan Ampersand Esper/Aurora Photos)

Coast redwoods in Henry Cowell Redwoods State Park, California (© Gallery Stock)

Hummingbird near blooming aloe plants in Laguna Beach, California (© Aurora Photos/Offset)

Prairie and pinnacles near Castle Trail in Badlands National Park, South Dakota (© Danita Delimont/Getty Images)

Newborn brown-throated sloth with mother, Sloth Sanctuary of Costa Rica (© Suzi Eszterhas/Minden Pictures)

The Glenfinnan Viaduct in Scotland (© Jon Arnold/DanitaDelimont.com)