French climber Alain Robert, also known as “Spiderman”, holds the flag of Nepal as he scales the Tour Montparnasse, a 210-metre (689 ft) building in central Paris, France April 28, 2015, to show support for the victims after the earthquake in Nepal. (Photo by Gonzalo Fuentes/Reuters)

A visitor tries out the new glass Skywalk at the top of the refurbished Blackpool Tower on September 1, 2011 in Blackpool, England. After a GBP Ј20 million refurbishment, the iconic seaside Blackpool Tower opened today to the general public. The observation deck at the top of the tower becomes the Blackpool Tower Eye and features a skywalk made of glass overlooking the sea and the promenade. The opening is part of Blackpool's GBP Ј250 million GBP regeneration project. (Photo by Christopher Furlong/Getty Images)

Men rest after salvaging metal on the 30th floor of the “Tower of David” skyscraper in Caracas February 3, 2014. A 45-storey skyscraper in the center of Venezuela's capital Caracas is a slum, probably the highest in the world. Dubbed the “Tower of David”, the building was intended to be a shining new financial center but was abandoned around 1994 after the death of its developer – banker and horse-breeder David Brillembourg – and the collapse of the financial sector. (Photo by Jorge Silva/Reuters)

Kent Josephso organizes his 8mm tracer rounds during the Big Sandy Shoot in Mohave County, Arizona March 23, 2013. The Big Sandy Shoot is the largest organized machine gun shoot in the United States attended by shooters from around the country. Vintage and replica style machine guns and cannons are some of the weapons displayed during the event. Picture taken March 22, 2013. (Photo by Joshua Lott/Reuters)

General view of the stands in the Atrium during the Big Fashion Wardrobe Spring/Summer fashion and beauty event at Westfield London shopping centre on March 29, 2011 in London, United Kingdom.

National Geographic photographer Steve Winter has spent most of his adult life shooting wild cats. Photo: A 14-month-old cub, cooling off in a pond, is riveted by a deer that appeared near the shore. Tigers are powerful swimmers; they can easily cross rivers four to five miles wide and have been known to swim distances of up to 18 miles. (Photo by Steve Winter/National Geographic)

Maintenance engineer Darren Unsworth cleans one of the crystal Edwardian chandeliers that illuminate Blackpool Tower Ballroom on January 16, 2012 in Blackpool, England. Blackpool's famous Tower Ballroom is undergoing an annual spring clean which includes lowering the ornate chandeliers where each shard of crystal is cleaned for the coming season of dancing. The dance floor consisting of 30,602 blocks of mahogany, oak and walnut is also sanded and polished to give the perfect dance floor. (Photo by Christopher Furlong/Getty Images)