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)

Kenichi Ito runs on his arms and legs on a race course on his way to setting the Guinness World Record fastest time for the 100-meter dash on all fours at Komazawa Olympic Park Stadium in Tokyo Thursday, November 14, 2013. The 30-year-old Japanese finished in 16.87 seconds Thursday, shaving more than half a second off his 2012 run of 17.47. (Photo by Shizuo Kambayashi/AP Photo)

“Hiding In The Shadows”. This Baby Sandhill taking refuge under Moms wings while sitting on her second egg. I witnessed this baby being born earlier that day,and the next morning saw the other one hatch,what a sight to see. Photo location: Deland, Florida. (Photo and caption by Scott Helfrich/National Geographic Photo Contest)

An ice swimming enthusiast dressed as Neptune takes to the frigid waters of Orankesee lake during the 27th annual "Winter Swimming in Berlin" on January 8, 2011 in Berlin, Germany. A local swimmers' group called the “Berlin Seals” invite ice swimmers from across Germany and abroad to the annual event. Members claim ice swimming is good for the body's blood circulation. (Photo by Sean Gallup)

Highly commended birds : Crested guan by Tim Hunt (UK). ‘This photo shows a crested guan in the cloud forests of Costa Rica as it pauses while foraging on a lone branch. Due to the clouds that are so typical for this habitat, I could often only photograph the bird’s silhouette against a grey sky. But then, for a short moment only, the sun broke through the clouds, and I overexposed the image by over two stops in order to blow out the background and allow this beautifully marked bird to stand out’. (Photo by Tim Hunt/GDT European Wildlife Photographer of the Year 2015)

An Indian worker paints the hand of a huge clay model of a tribal woman on the Indian state of Karnataka's tableau for Republic Day parade, in New Delhi, India, Friday, January 22, 2016. Security has been tightened around the Indian capital as well as across the country ahead of Republic Day celebrations, held each year on Jan. 26. (Photo by Manish Swarup/AP Photo)

A man carries an injured girl after what activists said were five air strikes by forces loyal to Syria's President Bashar al-Assad in Douma, eastern al-Ghouta, near Damascus September 11, 2014. (Photo by Bassam Khabieh/Reuters)

In this third of seven sequential photos, Elian Gonzalez is held in a closet by Donato Dalrymple, one of the two men who rescued the boy from the ocean, right, as government officials search the home of Lazaro Gonzalez for the young boy, early morning, April 22, 2000, in Miami, Florida. Armed federal agents seized Elian Gonzalez from the home of his Miami relatives before dawn, firing tear gas into an angry crowd as they left the scene with the weeping 6-year-old boy. This photo won the Prize in 2001. (Photo by Alan Diaz/AP Photo)