This combination of April 15, 2013 and April 2, 2014 photos show a police officer clearing Boylston Street following a bomb blast near the finish line of the 2013 Boston Marathon, and pedestrians crossing at the same corner nearly a year later in Boston. (Photo by Charles Krupa/AP Photo)

A man wearing a “Pinhead” mask walks through the grounds of St Mary's Church, Whitby, during the Whitby Gothic festival taking place this weekend, on April 27, 2014. The twice yearly event attracts Goths from across the UK and beyond to the historic fishing town and is a great boost to the local economy. (Photo by Anna Gowthorpe/PA Wire)

An elephant from Earl's Court Circus with a man in its mouth, 1928. P.S. All pictures are presented in high resolution.

Workers demonstrate outside the factory of Hua Yang Printing Holdings Co Ltd on October 30, 2007 in Shenzhen of Guangdong Province, China. Over 1,000 workers of the company have blocked the 107 State Highway where the firm is located, to protest against their employer, who owed half a month's salary to the workers. (Photo by China Photos/Getty Images)

Henry Frayne of Australia shows his ability to triple jump the lenghth of more than two Formula 1 cars during a press conference at Albert Park on February 29, 2012 in Melbourne, Australia. (Photo by Robert Prezioso/Getty Images)

1: Dubai's Burj Khalifa is the tallest building in the world, but perhaps not for long. Saudi Arabia has announced plans to build a 1 kilometer (3,280 foot) tower into the sky, to be named the Jeddah Tower, scheduled for completion in 2020. The Burj Khallifa currently stands at 2,716 ft. (Photo by Matthias Seifert/Reuters)

Daniel J. Wabsey, a 58-year-old war veteran, sits outside his tent at Camp Hope in Las Cruces, New Mexico October 6, 2015. “I've been traveling for 35 or 38 years. Getting inside would take a while to get used to. I just want to be able to eat, sleep and be safe. We all get along and understand in Camp Hope. We've all been there. With common sense you can survive out here”, Wabsey said. Camp Hope describe themselves as an “alternative transitional living project for the homeless”. Around 50 people live at the camp. (Photo by Shannon Stapleton/Reuters)

A man rides a horse at a playground on a hill in Kabul April 19, 2015. (Photo by Mohammad Ismail/Reuters)