A man standing on the first cables during the construction of the Golden Gate Bridge with the Presidio and San Francisco in the background, San Francisco, California, 1935. (Photo by Underwood Archives/Getty Images)

A Buddhist nun walks along a path as a stupa is seen at a temple in Anuradhapura, Sri Lanka October 16, 2016. (Photo by Dinuka Liyanawatte/Reuters)

This April 30, 2016 image made available by NOAA shows a deep sea anglerfish living between pillow basalt rock formations, during a deepwater exploration of the Marianas Trench Marine National Monument area in the Pacific Ocean near Guam and Saipan. The ambush predator waits for prey to be attracted by its lure, located between its eyes, and gulps it with its large mouth. (Photo by NOAA Office of Ocean Exploration and Research via AP Photo)

Sunrise over a moor viewed from Littaford Tor, Dartmoor, UK, 2016. Autumn visits the windswept moors and granite tors of Dartmoor earlier than the rest of the south-west. While there aren’t many trees here, autumn shades appear in golden ferns and tan heather. Littaford Tors, near Two Bridges and a mile from Princetown, is a short walk and can be combined with a visit to the adjacent Wistman’s Wood. (Photo by Stuart Holmes)

The moon rises behind the skyline and financial district in Toronto, November 25, 2015. (Photo by Mark Blinch/Reuters)

A man pulls a cart with collapsed cardboard boxes past boutiques in the Sinchon district in Seoul, May 5, 2015. (Photo by Thomas Peter/Reuters)

A wide-angle view shows the ascent of the shuttle Challenger on January 28, 1986. In the seconds after ignition, the rocket engines' hot blast began the process of destruction. (Photo by NASA)

An empty cell block is pictured within Joint Task Force Guantanamo's Camp VI at the U.S. Naval Base in Guantanamo Bay, Cuba March 22, 2016. (Photo by Lucas Jackson/Reuters)