Tulip fields in Noordoostpolder, Netherlands (© Siebe Swart/plainpicture)(Bing United States)

Rocky shoreline in Saguenay-St. Lawrence Marine Park, Quebec, Canada (© Yves Marcoux/plainpicture)(Bing United States)

Sway bridge at the Palace of the Lost City, North West Province, South Africa (© Heinrich van den Berg/Alamy)(Bing United States)

The Koknese Castle ruins in Koknese, Latvia (© Andrejs Zemdega/Getty Images)(Bing United States)

Aztec headdress detail (© Marcia Chambers/Alamy)(Bing United States)

Pass over the Atlas Mountains above the Dadès Gorges, Morocco (© Art Wolfe/Mint Images)(Bing United States)

Cambridge University Botanic Garden, Cambridge, England (© Harpur Garden Library/Corbis)(Bing United States)

Poplar trees in Po Valley, Italy (© Eddy Galeotti/Alamy)(Bing United States)

Snow goose migration at the Saint-François River, Quebec, Canada (© David Doubilet/Getty Images)(Bing United States)

Mother wolf and pup (© Ronald Wittek/age fotostock)(Bing United States)

Tatuamunha River estuary, Brazil (© Luciano Candisani/Minden Pictures)(Bing United States)

Marina Bay skyline in Singapore (© Martin Puddy/Getty Images)(Bing United States)

Boats moored in the Vieux-Port, Cannes, France (© Alan Copson/age fotostock)(Bing United States)

Tidal flats, Katmai National Park, Alaska (© plainpicture/Cultura)(Bing United States)

Black-tailed prairie dogs in Wind Cave National Park, South Dakota (© James Hager/age fotostock)(Bing United States)

US Navy F/A-18F Super Hornet creating a sonic boom (© Darek Siusta/REX)(Bing United States)

Mount St. Helens, Washington (© Diane Cook and Len Jenshel/Getty Images)(Bing United States)

Flower hat jelly in the Monterey Bay Aquarium, Monterey, California (© Frans Lanting/plainpicture)(Bing United States)

The Colorado River and Marble Canyon, Grand Canyon National Park, Arizona (© Gavin Heffernan/Shutterstock)(Bing United States)

Crater Lake, Oregon (© Roshin Lal Ramesan)(Bing United States)

Red-eared slider turtle (© Ammit Jack/Alamy)(Bing United States)

Sand dune, Sossusvlei, Namibia (© Erik Joosten/Minden Pictures)(Bing United States)

Lantern floating ceremony at Ala Moana Beach Park, Oahu, Hawaii (© Douglas Peebles Photography/Alamy)(Bing United States)

Horned grebe carrying its chick (© Winfried Wisniewski/Minden Pictures)(Bing United States)

A fog-shrouded Golden Gate Bridge in San Francisco (© Della Huff/Alamy)(Bing United States)

Cherry orchards bloom in Mason County, Michigan (© Jeffrey Wickett/SuperStock)(Bing United States)

Sơn Đoòng Cave in Phong Nha-Kẻ Bàng National Park, Vietnam (© Getty Images)(Bing United States)

Herd of impalas in Masai Mara National Reserve, Kenya (© Jonathan & Angela Scott/Getty Images)(Bing United States)

A living bridge in the East Khasi Hills district of Meghalaya, India (© Timothy Allen/Getty Images)(Bing United States)