A porcini mushroom (© vnosokin/Getty Images)

Porto Flavia, Sardinia, Italy (© Visualframing/Adobe Stock)

The 'Alien Egg Hatchery' in the Bisti/De-Na-Zin Wilderness, New Mexico (© Ian Shive/Tandem Stills + Motion)

Anna's hummingbird (© Dee/Getty Images)

The Regata Storica on the Grand Canal in Venice, Italy (© Alexander Duffner/Alamy)

Park service employees inspecting Mount Rushmore National Memorial, South Dakota (© Universal Images Group via Getty Images)

Humpback whales off the coast of Massachusetts (© Eric Kulin/plainpicture)

Livraria Lello, a bookstore in Porto, Portugal (© Nido Huebl/Shutterstock)

San Juan Islands, Washington (© Stephen Matera/Tandem Stills + Motion)

River Avon in Bath, England (© Robert Harding World Imagery/Offset by Shutterstock)

US flag on part of a 9/11 memorial overlooking the New York skyline from Exchange Place, Jersey City, New Jersey (© Gary Hershorn/Getty Images)

Asian elephants in West Bengal, India (© Avijan Saha/Minden Pictures)

Aerial view of the Venice Skatepark in Venice Beach, Los Angeles (© Ingus Kruklitis/Getty Images)

Aldeyjarfoss waterfall in northern Iceland's interior landscape (© Jim Patterson/Tandem Stills + Motion)

Artist Jesus 'CIMI' Alvarado painting his mural 'Fronterizos' on a wall of the El Paso Museum of Art, El Paso, Texas (© Paul Ratje/AFP via Getty Images)

Palacio de Bellas Artes, Mexico City, Mexico (© Lukas Bischoff Photograph/Shutterstock)

Benagil Cave in the Algarve, Portugal (© Michael Malorny/Offset by Shutterstock)

Red panda at the Chengdu Panda Base in Sichuan province, China (© Biosphoto/Alamy)

Le Castella at Capo Rizzuto, Italy (© mRGB/Shutterstock)

Starlings in the wetlands between Denmark and Germany (© Viking/Alamy)

'Rising Moon' lantern to celebrate the Mid-Autumn Festival in Hong Kong's Victoria Park (© Bobby Yip/Reuters)

Neptune (© NASA/JPL)

Cusco Cathedral on the Plaza de Armas, Cusco, Peru (© sharptoyou/Shutterstock)

Escarpment Trail in Porcupine Mountains Wilderness State Park, Michigan (© Pat & Chuck Blackley/Alamy)

The Mackenzie River in Canada emptying into the Beaufort Sea (© Norman Kuring, GSFC/NASA/USGS Landsat)

Thorn bug, Pico Bonito National Park, Honduras (© Mac Stone/Tandem Stills + Motion)

Mount Fuji in Japan (© The Asahi Shimbun/Getty Images)

A wood bison near Behchoko, in the Northwest Territories, Canada (© Don Johnston/agefotostock)

Container ship in San Pedro, California (© Cameron Venti/Getty Images)