Wimbachklamm, Ramsau, Bavaria, Germany (© Westend61 GmbH/Alamy)

Aerial view of Daintree River and rainforest, Australia (© Peter Adams/Offset)

Red squirrel in heather, Scotland (© Christopher Drabble/Alamy)

Wimbachklamm, Ramsau, Bavaria, Germany (© Westend61 GmbH/Alamy)

Tegallalang terrace farms in Ubud, Bali, Indonesia (© gorgeoussab/Shutterstock)

Castillo San Felipe del Morro in Old San Juan, Puerto Rico (© grandriver/Getty Images)

Mount Fanjing, the highest peak of the Wuling Mountains, in southwest China (© Keitma/Alamy)

Central Coast vineyards in Arroyo Grande, California (© Ian Shive/Tandem Motion + Stills)

Gerenuk in Tsavo National Park, Kenya (© Byrdyak/iStock/Getty Images Plus)

鸟瞰雨林和丹特里河，澳大利亚 (© Peter Adams/Offset)

Drones light up the sky over Shenzhen, China (© Liang Weiming/VCG via Getty Images)

Maple leaves in autumn (© Katsuaki Shoda/EyeEm/Getty Images)

Walruses near Kvitøya in the Svalbard archipelago, Norway (© Ole Jorgen Liodden/Minden Pictures)

Surfboards in a row (© plainpicture/Tony Arruza)

Wachsenburg Castle, Drei Gleichen, Thuringia, Germany (© Raimund Linke/Masterfile)

The Villarrica volcano in Chile on September 2, 2018 (© Cristobal Saavedra Escobar/Reuters)

Coniferous forest, Vosges Mountains, France (© Radomir Jakubowski/Minden Pictures)

A common loon in the Superior National Forest, Minnesota (© Jim Brandenburg/Minden Pictures)

Pando, a quaking aspen grove in Fishlake National Forest, Utah (© Don Paulson/Danita Delimont)

Gewürztraminer grapes at autumn harvest, Okanagan Valley, B.C., Canada (© Henry Georgi/age fotostock)

Aerial view of forest, Vancouver, B.C., Canada (© Michael Wu/EyeEm/Getty Images)

Equinox at the Temple of Kukulcan in Chichen Itza, Mexico (© Somatuscani/Getty Images Plus)

Arctic surfing trip in the Lofoten Islands, Norway for the Lofoten Masters (© Nicolás Pina/Tandem Stills + Motion)

Surfers in the Lofoten Islands, Norway (© Nicolás Pina/Tandem Stills + Motion)

Sea otters in Alaska’s Inside Passage (© Erika Skogg/Getty Images)

Colorful sunset over Castildetierra, in the Natural Park of Bardenas Reales, Navarre, Spain (© Inigofotografia/iStock/Getty Images Plus)

Blooming jacaranda trees in New Farm Park, Brisbane, Australia (© Walter Bibikow/Danita Delimont)

Autumnal landscape near the town of Clavijo in Spain's Rioja district (© Olimpio Fantuz/eStock Photo)

Coffee cherries in Quindío, Colombia (© The Colombian Way Ltda/Getty Images)