Brave slackliners have been pictured walking the ropes above Rio de Janeiro, Brazil on August 15, 2016, with the half a mile drop showing the city in all its glory. The stunning shots show the daredevils tread across an eighty-two-foot-long high line on Pedra da Gvea mountain with an amazing sunrise illuminating the city landscape behind. (Photo by Rafael Moura/Caters News Agency)

A workman takes a siesta on a girder during the building of Radio City, the city of New York spread out below. (Photo by General Photographic Agency/Getty Images). Circa 1933

A demonstrator carries a placard reading “One more day of reflection” as she dances with others at Sol Square on May 21, 2011 in Madrid, Spain. A growing number of angry Spaniards have, encouraged by youth groups and social media campaigns, taken possession of the Sol square setting it up with tents and kitchens ahead of Sundays regional and municipal elections held in Spain. (Photo by Jasper Juinen/Getty Images)

A worker pauses for a sandwich, resting on a girder during the construction of a skycraper. (Photo by Hulton Archive/Getty Images). Circa 1930

Battersea Power Station. The chimney rims are thinner on top than you might expect. (Photo by Bradley L. Garrett)

Commuters ride on the roof of a Jakarta state rail train at Cawang train station on January 27, 2012 in Jakarta, Indonesia. (Photo by Ulet Ifansasti/Getty Images)

New York Police Department tactical police officers stand guard near the New York Stock Exchange on September 9, 2011 in New York City. Officials are stepping up security in New York and Washington D.C. a day after U.S. officials received a credible but unconfirmed terror threat to utilize car bombs on bridges or tunnels in New York or Washington. (Photo by Justin Sullivan/Getty Images)

An Israeli tank moves into position in the Israeli controlled Golan Heights during fighting between forces loyal to Syrian President Bashar Assad and rebels in the Druze village of Khader in Syria, Tuesday, June 16, 2015. As many as 20 members of the Druze minority sect were killed last week, the deadliest violence against the Druze since Syria's conflict started in March 2011, sparking fears of a massacre against the sect. (AP Photo/Ariel Schalit)