Grape hyacinths and tulips, Keukenhof Gardens, Lisse, Netherlands (© Martin Ruegner/Getty Images)

Belém Tower on the bank of the Tagus River, Lisbon, Portugal (© f9photos/Getty Images)

Spectacled bear resting in tree, Ecuador (© Andy Rouse/Nature Picture Library)

The glass dome of Galleria Vittorio Emanuele II, Milan, Italy (© PhillipMinnis/Getty Images)

Pink apple blossoms, Avila Beach, California, United States (© Mimi Ditchie Photography/Getty Images)

Galápagos penguins swimming, Galápagos Islands, Ecuador (© Henley Spiers/Nature Picture Library)

Forest hammock of slash pine and saw palmetto, Everglades National Park, Florida, United States (© Mary Liz Austin/Alamy)

Common chiffchaff, Germany (© Andyworks/Getty Images)

Alam-Pedja Nature Reserve in Tartu County, Estonia (© Sven Zacek/Nature Picture Library)

European hedgehog, France (© Klein & Hubert/Nature Picture Library)

Sunset in Canyonlands National Park, Moab, Utah, United States (© Jason Hatfield/Tandem Stills + Motion)

Mirror Beach, Porto Seguro, Bahia, Brazil (© Marcelo Nacinovic/Getty Images)

Rolling hills of Tuscany, Italy (© Andyworks/Getty Images)

Grey-headed flying fox carrying her pup, Yarra Bend Park, Australia (© Doug Gimesy/Nature Picture Library)

Skagit Valley Tulip Fields, Washington, United States (© Alan Majchrowicz/Getty Images)

Pine trees reflected in the Forgetmenot Pond in Kananaskis Country, Alberta, Canada (© chinaface/Getty images)

Common clownfish in a sea anemone, Raja Ampat Islands, Indonesia (© Magnus Lundgren/Nature Picture Library)

Milky Way over Anza-Borrego Desert State Park, California, United States (© Kevin Key/Slworking)/Getty Images)

City lights streak below, taken from the International Space Station (© NASA)

Papagayo Beach, Lanzarote, Canary Islands, Spain (© Gavin Hellier/Getty Images)

Two young red foxes at Karula National Park, Estonia (© Sven Zacek/Nature Picture Library)

Sgwd yr Eira waterfall, Bannau Brycheiniog National Park, Wales (© Guy Edwardes/Nature Picture Library)

Seattle, Washington, United States (© Jim Patterson/Tandem Stills + Motion)

Beaver, Germany (© Andyworks/Getty Images)

Hirosaki Castle with cherry blossoms, Hirosaki, Japan (© Glenn Waters/Getty Images)

Lake Gentau in the French Pyrenees, Pyrénées-Atlantiques, France (© MICHAUX Stéphane/Hemis.fr/Alamy)

Black grouse males facing off on a lekking site, Estonia (© Sven Zacek/Nature Picture Library)

Armbrug bridge, Amsterdam, Netherlands (© Alexander Spatari/Getty Images)

Wildflower bloom, Central Valley, California, United States (© Jeff Lewis/Tandem Stills + Motion)

Japanese tree frog in a pink morning glory (© Tetsuya Tanooka/Getty Images)