Castle of Zafra, Guadalajara province, Spain (© Eduard Gene/Getty Images)

Pueblo ruins, Hovenweep National Monument, Utah (© Alan Majchrowicz/Getty Images)

American bison in Yellowstone National Park, Wyoming (© Ian Shive/TANDEM Stills + Motion)

Caribbean flamingo nests, Ría Lagartos Biosphere Reserve, Yucatán, Mexico (© Claudio Contreras/Minden Pictures)

Grasmere, Lake District, Cumbria, England (© Thomas Molyneux/Getty Images)

Autumn sunrise over the National Mall, Washington, DC (© WLDavies/iStock/Getty Images Plus)

Shi Shi Beach in Olympic National Park, Washington (© T.M. Schultze/TANDEM Stills + Motion)

Vancouver Coastal Sea wolves in Great Bear Rainforest, British Columbia, Canada (© Nick Garbutt/Alamy)

Aerial view of glacial rivers in Iceland (© rybarmarekk/Shutterstock)

Milky Way, Aït Benhaddou, Morocco (© Cavan Images/Getty Images)

Caribbean flamingos, Yucatán Peninsula, Mexico (© Claudio Contreras/NPL/Minden Pictures)

Mural Wall, Korean War Veterans Memorial, Washington, DC (© Steve Tulley/Alamy)

Double Arch seen through Cove Arch, Arches National Park, Utah (© Jeff Foott/Minden Pictures)

California sea lion in a forest of giant kelp, Baja California, Mexico (© Claudio Contreras/Minden Pictures)

Manarola, Cinque Terre National Park, Liguria, Italy (© John_Silver/Shutterstock)

Yi Peng lantern festival, Chiang Mai, Thailand (© tampatra/Getty Images)

Wadden Sea coast, near Moddergat, Friesland, Netherlands (© Ron ter Burg/Minden Pictures)

Red deer stag in the Caledonian Forest, Glen Affric, Scottish Highlands (© Terry Whittaker/Alamy)

Porthcawl Lighthouse, Wales (© Leighton Collins/Alamy)

Tasmans Arch, Tasmania, Australia (© Gary Bell/Minden Pictures)

Giant land art painting 'Beyond Crisis' by Saype, Leysin, Switzerland (© VALENTIN FLAURAUD/EPA-EFE/Shutterstock)

Lion cubs at sunrise, South Africa (© Ruan Springorum/Getty Images)

Spiral aloe, Kangaroo Island, Australia (© Michael Melford/Alamy)

Sonoma Coast State Park, California (© Rachid Dahnoun/Tandem Stills + Motion)

Masai giraffes, Amboseli National Park, Kenya (© Art Wolfe/DanitaDelimont.com)

Olive grove, Valle d'Itria, Puglia, Italy (© Massimo Santi/Shutterstock)

Tombeau du Géant (Giant's Tomb) in autumn, Bouillon, Belgium (© David Briard/Getty)

Wild turkeys, New York (© John Cancalosi/Alamy)

Mont-Saint-Michel, Normandy, France (© Captain Skyhigh/Getty Images)

Kilchurn Castle reflected in Loch Awe, Argyll and Bute, Scotland (© Tom Mackie/plainpicture)