Negratín Reservoir, Granada, Spain (© Andres Martinez Olmedo/Getty Images)

Killer whales in the waters off Spildra, Norway (© Alex Mustard/Minden Pictures)

Killer whales in Spildra, Norway (© Alex Mustard/Minden Pictures)

Icelandic horses standing in a field, Iceland (© Rodrigo Lourezini/Shutterstock)

Aerial view of terraced rice fields, Yuanyang County, China (© AlexGcs/Getty Images)

Holi celebrations, Nandgaon, Uttar Pradesh, India (© Avishek Das/Getty Images)

Aurora display, Whitehorse, Yukon, Canada (© John Hyde/plainpicture/Design Pics)

Edale Valley, Peak District, England (© John Finney/Getty Images)

Marshland, Gloucester, Massachusetts (© Thomas H. Mitchell/Getty Images)

National Theatre, Cluj-Napoca, Romania (© Thomas Mueller/Shutterstock)

Lionesses sleeping, Serengeti National Park, Tanzania (© Cavan Images/Shutterstock)

Lionesses sleeping, Serengeti National Park, Tanzania (© Cavan Images/Shutterstock)

Underwater river scene with freshwater plants and tetra fish, Aquário Natural, Rio Baia Bonito, Mato Grosso do Sul, Brazil (© Michel Roggo/Minden Pictures)

Giant panda at Chengdu Panda Base, China (© Jim Zuckerman/Jaynes Gallery/DanitaDelimont)

Ballyvooney Cove, Copper Coast Geopark, Ireland (© Andrea Pistolesi/Getty Images)

Great cormorants gliding through a snowstorm in Hesse, Germany (© Wilfried Martin/Getty Images)

Barn owl, England (© Ondrej Prosicky/Getty Images)

Crocus flowers (© Raimund Linke/Getty Images)

Colorful pastel chalk (© Stephen Shepherd/plainpicture)

Colourful pastel chalk (© Stephen Shepherd/Plainpicture)

Lenticular clouds, Patagonia (© Sasha Juliard/Shutterstock)

Blooming wild garlic, Hainich National Park, Germany (© Frank Sommariva/Getty Images)

Cecil Brewer Staircase, the Heal's Building, London, England (© Yiran An/Getty Images)

Cecil Brewer Staircase, London, England (© Yiran An/Getty Images)

New York City skyline in fog (© Orbon Alija/Getty Images)

New York City skyline in the clouds (© Orbon Alija/Getty Images)

Manatees, Crystal River, Florida (© Gregory Sweeney/Getty Images)

Peacock feathers (© Sarayut Thaneerat/Getty Images)

Steyr River, Austria (© guenterguni/Getty Images)

Javan tree frog (© kuritafsheen/Getty Images)