A tour group wanders through block 7 of Eastern State Penitentiary in Philadelphia, Pennsylvania April 30, 2014. Opened in 1829, with the original corrective system of “confinement in solitude with labor”, the penitentiary housed about 75,000 inmates in its 142 years of operation. At Eastern State reunions, former inmates, staff and guard gather to share memories and trade stories and get a chance to describe their experiences in question-and-answer sessions with the public. (Photo by Mark Makela/Reuters)

A British Army Rolls Royce armoured car outside the Royal Ulster Constabulary police station on York Street in Belfast following riots after an Orange Order parade. (Photo by Fox Photos/Getty Images). 20th June 1935

The summit of one of Europe's tallest mountains glows like the flame of a candle as the sun rises on a clear morning. The Matterhorn, famous for appearing on bars of Toblerone chocolate bars, reflects the vivid orange light at 5.37am. (Photo by Margarethe Jaeger/Solent News & Photo Agency)

Britain's biggest dog, 18 month old great Dane, Freddy seen realxing on the sofa with it's owner Claire Stoneman at their home in Southend-on-Sea, Essex, England. (Photo by Matt Writtle/Barcroft Media)

A visitor wears an outfit as she watches the St. George NextGen show for Fashion Week in Sydney on May 16, 2017. (Photo by Peter Parks/AFP Photo)

A hyena kisses his own reflection while appearing to walk on water. (Photo by Jake De Wet/Caters News Agency)

Japanese hairdresser Megumi Takeichi cuts patterns into the hair of a camel ahead of the Bikaner Camel Festival in Bikaner in the western Indian state of Rajasthan on January 10, 2019. (Photo by Dinesh Gupta/AFP Photo)

The “EMIEW3” robot (R) demonstrates communicating with a visitor during a press preview in Tokyo on April 8, 2016. Japanese electronics giant Hitachi unveiled its humanoid customer service and guidance robot “EMIEW3” and “remote brain” robotics IT platform. (Photo by Toshifumi Kitamura/AFP Photo)