A woman react inside a cloud of paint powder during the holi one colour Festival held in the city of Cape Town, South Africa, Saturday, March 2, 2013. Thousands of people are taking part in the festival by throwing coloured paint powder at each other to express freedom and the colour of everyday life. (Photo by Schalk van Zuydam/AP Photo)

A view of an entrance to the concrete case surrounding the pressure vessel of the reactor is seen inside the decommissioned Unit Six of the Greifswald nuclear power station outside Lubmin August 5, 2014. Unit Six was a part of East Germany's largest nuclear power plant that was nearly completed in 1990, when the country's re-unification halted construction. (Photo by Thomas Peter/Reuters)

A Turkana boy herds cows as he carries a rifle in north western Kenya near the town of Kibish inside the Turkana region of the Ilemy Triangle September 26, 2014. The Turkana people have historically clashed over ethnic differences and precious resources such as fishing, pasture and fresh water with other tribes bordering their territory, such as the Dassanach from southern Ethiopia. (Photo by Goran Tomasevic/Reuters)

This photographer is walking on thin ice after taking stunning photographs inside an Alaskan ice cave that could collapse at any moment. With it's dazzling turquoise walls and and huge open spaces, it's hard to imagine that this incredible frozen cavern was only formed at the beginning of 2012. But despite it's seemingly mystical allure, the fascinating natural phenomena is at risk of collapsing in on itself without warning. (Photo by Ron Gile/Caters News)

In this February 2, 2014 photo, people take pictures inside a cave at Apostle Islands National Lakeshore in northern Wisconsin, which has been transformed into a dazzling display of ice sculptures by the arctic siege gripping the Upper Midwest. (Photo by Brian Peterson/AP Photo/Minneapolis Star Tribune)

Jill Olsen (R) has her picture taken inside a giant cocoon, from the “Falling Skies” TV series, during the 2014 Comic-Con International Convention in San Diego, California July 24, 2014. (Photo by Sandy Huffaker/Reuters)

Photographer uses pinhole camera in his mouth to capture photos around the world. The 52-year-old Justin Quinnell, who lives in Bristol, is known for his eye-catching photographs taken from a unique angle – right inside his mouth. (Photo by Justin Quinnell/Rex Features)

A Cuban migrant couple rests inside a tent at a provisional shelter in Paso Conoa, at the border with Costa Rica March 20, 2016. More than 1,500 Cuban immigrants are waiting at Costa Rica's southern border with Panama as they seek overland passage towards the United States, according to local officials. (Photo by Carlos Jasso/Reuters)