A women sits on the south rim of Grand Canyon National Park in northern Arizona, April 12, 2015. (Photo by Jim Urquhart/Reuters)

A couple chats at a park during sunset in Chihuahua November 15, 2014. (Photo by Jose Luis Gonzalez/Reuters)

A baby elephant eats in a swamp in Amboseli national park, Kenya, March 19, 2017. (Photo by Goran Tomasevic/Reuters)

A tomtit bird flies past a squirrel running on a fence after a snowfall in a park in Almaty, Kazakhstan, January 12, 2016. (Photo by Shamil Zhumatov/Reuters)

Cambodian children sleep on a pavement at a park in Phnom Penh on July 8, 2016. (Photo by Tang Chhin Sothy/AFP Photo)

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 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)