The Gateway Arch in St. Louis, Missouri (© f11photo/Getty Images)

National Museum of African American History & Culture, Washington, DC (© BrianPIrwin/Shutterstock)

Young alpine marmot (© Jonas Fichtner-Pflaum/Getty Images)

Ribblehead Viaduct and Ingleborough mountain, North Yorkshire, England (© AWL Images/DanitaDelimont.com)

Golden Bridge, Bà Nà Hills, Da Nang, Vietnam (© Hien Phung Thu/Shutterstock)

Scottish Blackface sheep, Aberdeenshire, Scotland (© Mike Powles/Getty Images)

Archway Islands, Wharariki Beach, South Island, New Zealand (© Francesco Vaninetti/AWL/plainpicture)

Blue hour in Trondheim, Norway (© Jeanny Mueller/Getty Images)

Medieval towers in Mestia, Upper Svaneti, Georgia (© photoaliona/Getty Images)

Alstrom Point, Lake Powell, Utah (© T.M. Schultze/TANDEM Stills + Motion)

Art installation of umbrellas at Borough Market in London, England (© Malcolm P Chapman/Getty Images)

Yungang Grottoes, Datong, Shanxi province, China (© Eric Yang/Getty Images)

Marine iguanas, Galápagos Islands, Ecuador (© helovi/Getty Images)

Lake Tyrrell, Victoria, Australia (© Monica Bertolazzi/Getty Images)

Magellanic penguins in the Falkland Islands (© Vicki Jauron, Babylon and Beyond Photography/Getty Images)

Icicles of Misotsuchi, Chichibu, Japan (© watayu0821/Shutterstock)

Humpback whale mother and calf, Tonga (© Chase Dekker/Minden Pictures)

The Washington Monument seen from the Lincoln Memorial, Washington, DC (© lucky-photographer/Alamy)

Great Blue Hole, Belize (© JamiesOnAMission/Shutterstock)

European river otter, Lelystad, Netherlands (© Ernst Dirksen/Minden Pictures)

Alpenglow on Half Dome, Yosemite National Park, California (© Matthew Kuhns/TANDEM Stills + Motion)

Champaka Sarasi pond near Shivamogga, Karnataka, India (© Amith Nag Photography/Getty Images)

Mount Fuji at sunrise, Lake Kawaguchi, Japan (© Twenty47studio/Getty Images)

Group of giant cuttlefish in Spencer Gulf, off Whyalla, South Australia (© Gary Bell/Minden Pictures)

Sandstone hoodoos, Bryce Canyon National Park, Utah (© Stephen Matera/TANDEM Stills + Motion)

Castle Stalker on Loch Laich, Argyll, Scotland (© WLDavies/Getty Images)

Polar bear cub, Churchill, Manitoba, Canada (© Eric Baccega/NPL/Minden Pictures)

Paro Taktsang, a Buddhist monastery in Bhutan (© Baron Reznik/Getty Images)