Ubehebe Crater in Death Valley National Park, California (© Albert Knapp/Alamy)

Barley field in East Lothian, Scotland (© Scott Masterton/plainpicture)

Mesas, Upper Cathedral Valley, Capitol Reef National Park, Utah (© Tim Fitzharris/Minden Pictures)

Wachsenburg Castle near Erfurt, Germany (© Radius Images/Offset by Shutterstock)

Clouded leopard (© Dhritiman Mukherjee/Alamy)

The Sky Pool at Embassy Gardens in London, England (© Xinhua News Agency/Getty Images)

Salisbury Crags in Holyrood Park overlooking Edinburgh, Scotland (© Andrew Merry/Getty Images)

Salt cones on Salar de Uyuni, Bolivia (© John Shaw/Minden Pictures)

Elizabeth Quay Bridge in Perth, Australia (© Amazing Aerial Agency/Offset by Shutterstock)

Māori rock carving by Matahi Whakataka-Brightwell, Lake Taupo, North Island, New Zealand (© Evgueni Zverev/Alamy)

The Smithsonian Arts and Industries Building in Washington, DC (© Ron Blunt/Courtesy Smithsonian)

The Perseid meteor shower photographed at the Dinosaur Museum of Erenhot in Inner Mongolia, China (© bjdlzx/Getty Images)

African bush elephant herd, Okavango Delta, Botswana (© Juan-Carlos Munoz/Minden Pictures)

Horned ghost crab, Grand Anse, Praslin Island, Seychelles (© Ingo Schulz/Offset by Shutterstock)

Strandbad Tiefenbrunnen, a public pool on the shore of Lake Zürich, Switzerland (© Amazing Aerial Agency/Offset by Shutterstock)

Silhouette of Shambhala roller coaster at sunset in PortAventura Park, Salou, Tarragona, Spain (© Joaquim F. P./Getty Images)

Stairway to Heaven trail in Wawayanda State Park, New Jersey (© Leembe/Getty Images)

The Old Town of Dubrovnik, Croatia (© Jeremy Woodhouse/Getty Images)

Giant manta ray and a photographer off the Ningaloo Coast, Australia (© Shutterstock Premier)

Rub' al Khali desert on the border of Oman and the Emirate of Dubai (© Daniel Schoenen/Offset by Shutterstock)

Petit Minou Lighthouse in the roadstead of Brest, Finistère, France (© Mathieu Rivrin/Getty Images)

The shoreline of Olympic Coast National Marine Sanctuary, Washington state (© Chris Moore/Tandem Stills + Motion)

Little blue heron in Cuba (© Sergey Uryadnikov/Alamy)

Old surfboards lined up as a fence near Paia, Maui, Hawaii (© Matt Anderson Photography/Getty Images)

Peekaboo view of Angels Window on the North Rim of the Grand Canyon, Arizona (© Tim Fitzharris/Minden Pictures)

A sea swallow feeding on the tentacles of a blue button in Coffs Harbour, New South Wales, Australia (© Gary Bell/Minden Pictures)

Casa do Penedo (House of the Rock) in Portugal (© Olimpio Fantuz/eStock Photo)

Red-billed oxpeckers on an impala in Mpumalanga, South Africa (© Heini Wehrle/Minden Pictures)

Underground lake in Ruskeala Mountain Park, Karelia, Russia (© Konstantin Trubavin/Offset by Shutterstock)

Crater glow from Mount Mayon in the Philippines (© Per-Andre Hoffmann/Cavan)

Đurđevića Tara Bridge in Montenegro (© Hike The World/Shutterstock)