Cheetah cubs climbing acacia trees in Ngorongoro Conservation Area, Tanzania (© Paul Souders/Getty Images)

Ruins of a kasbah in Kalaat M'Gouna, Morocco (© Leonid Andronov/Getty Images)

An Australian koala perched in a gum tree overlooking the scenery (© juuce/Getty Images)

Snowy owl at Jones Beach, Long Island, New York (© Vicki Jauron/Getty Images)

Sunset at Ruby Beach in Olympic National Park, Washington state (© Adam Mowery/Tandem Stills + Motion)

Inca fortress of Sacsayhuamán near Cusco, Peru (© Susanne Kremer/eStock Photo)

Bronze sculpture of child and his grandfather caring of plants and flowers, Cordoba, Spain (© David M G/Alamy)

People looking at the crowded Avenue des Champs-Élysées from the Arc de Triomphe on May 8, 1945, Paris, France (© AFP via Getty Images)

People looking at the crowded Avenue des Champs-Élysées from the Arc de Triomphe on May 8, 1945, Paris, France (© AFP via Getty Images)

Burchell's zebra mother and foal in Rietvlei Nature Reserve, South Africa (© Richard Du Toit/Minden Pictures)

Carlton Gardens fountain and autumn trees catching the sunlight in front of the Royal Exhibition Building, Melbourne (© CBCK-Christine/iStock/Getty Images Plus)

Painted and leaded glass window panel on display at the Florence Nightingale Museum, London, England (© David Gee/Alamy)

Moose snacking on water lilies in Millinocket, Maine (© Scott Suriano/Getty Images)

Rice fields in the Sidemen Valley, with Mount Agung in the background, Bali, Indonesia (© Jon Arnold/Danita Delimont)

Rice fields in the Sidemen Valley with Mount Agung in the background, Bali, Indonesia (© Jon Arnold/Danita Delimont)

The Old Patriarch Tree of Grand Teton National Park, Wyoming (© George Sanker/Minden Pictures)

Fishing village of Henningsvær with Henningsvær Idrettslag Stadion, Nordland, Norway (© Viktor Posnov/Alamy)

Fishing village of Henningsvær with Henningsvær Idrettslag Stadion, Nordland, Norway (© Viktor Posnov/Alamy)

Asian elephant herd in Kaziranga National Park, Assam, India (© Parameswaran Pillai Karunakaran/Minden Pictures)

Fields of lavender and sunflowers with beehives in Provence, France (© leoks/Shutterstock)

Vineyard in the Adelaide Hills region, Australia (© Ben Goode/iStock/Getty Images Plus)

Reichenbach Falls, Bernese Oberland, Switzerland (© Chris Milne/Alamy)

A male yellow-bellied slider (© Marko Markovic Photography/Shutterstock)

Greenan Maze in County Wicklow, Ireland (© Peter Krocka/Shutterstock)

Greenan Maze in County Wicklow, Ireland (© Peter Krocka/Shutterstock)

Aerial view of Everglades National Park, Florida (© Tetra Images/Getty Images)

The long plumes of a three-flowered avens as it goes to seed (© Sunshine Haven Photo/Shutterstock)

Aerial view of Marley Beach, Bermuda (© Paul Zizka/plainpicture)

Aerial view of Marley Beach, Bermuda (© Paul Zizka/plainpicture)

Grey wolf with begging pup, Montana (© Tim Fitzharris/Minden Pictures)

Great Barrier Reef, Queensland, Australia (© AWL Images/Danita Delimont)