Boundary Waters Canoe Area Wilderness, Minnesota (© s.tomas/Shutterstock)

Camel thorn trees, Deadvlei, Namib-Naukluft Park, Namibia (© Inge Johnsson/Alamy)

Amalgamated Clothing Workers of America in a Labor Day parade, May 1915, Chicago (© Chicago Sun-Times/Chicago Daily News collection/Chicago History Museum/Getty Images)

Scotts Bluff National Monument in Gering, Nebraska (© Hawk Buckman/Getty Images)

Whale shark off the coast of Alifu Dhaalu Atoll, Maldives (© Bachir Moukarzel/Amazing Aerial Agency)

Aerial view of Plaza Mayor, Madrid, Spain (© AirPano LLC/Amazing Aerial Agency)

Great white egret, Hungary (© Markus Varesvuo/Nature Picture Library)

Sørvágsvatn lake, island of Vágar, Faroe Islands, Denmark (© Anton Petrus/Getty Images)

Trullo buildings in Alberobello, Apulia, Italy (© Feng Wei Photography/Getty Images)

Calcite Springs Overlook and Yellowstone River, Yellowstone National Park, Wyoming (© Rebecca L. Latson/Getty Images)