People dance in a park on a foggy day in Huai'an, Jiangsu province, China October 10, 2017. (Photo by Reuters/China Stringer Network)

A girl uses her mobile phone during the evening at the National Park in Khartoum, Sudan, April 24, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

The National parks department hosts the 30th annual “All-Women Lifeguard Tournament” in Sandy Hook NJ. July 30, 2014. (Photo by Anthony Causi)

A white whale wears a wreath at the Hakkeijima Sea Paradise aquarium-amusement park complex in Yokohama, Japan, on October 3, 2012. (Photo by Associated Press)

Central Park Zoo, New York, 1967. (Photo by Garry Winogrand)

Two stags fight in a wildlife park in Aurach near Kitzbuehel, in the Austrian province of Tyrol. (Photo by Kerstin Joensson/Associated Press)

A saddle-billed stork stands in the grassland at the Nairobi National Park near Nairobi, Kenya January 23, 2017. (Photo by Thomas Mukoya/Reuters)

Sunrise over Haleakala Crater, Haleakala National Park, Maui, Hawaii on April 26th, 2011. (Photo by Robert Bush/Alamy Stock Photo)