A man holds his umbrella during snowfall on the Areopagitou pedestrian street beneath the Acropolis hill during snowfall in Athens, Greece, January 10, 2017. (Photo by Alkis Konstantinidis/Reuters)

Revelers dance at a Jacarezinho samba school practice session ahead of Carnival celebrations on February 16, 2014 in Rio de Janeiro, Brazil. The Jacarezinho “favela” was previously controlled by drug traffickers and is now occupied by the city's Police Pacification Unit (UPP). Carnival officially begins February 28, but pre-Carnival celebrations are already underway. (Photo by Mario Tama/Getty Images)

A walker has left a handprint on a snow- covered tree trunk on Grosser Feldberg mountain in the Taunus mountain range, Germany, 16 January 2017. (Photo by Frank Rumpenhorst/DPA)

Partially constructed notched burial plots are seen at the construction site of an underground tunnel designated for traditional Jewish burial at the Givat Shaul cemetery, on May 14, 2015, in Jerusalem, Israel. Underground cemetery being built by the Israeli Burial Society in Jerusalem due to a decrease in available land for traditional Jewish burials. (Photo by David Vaaknin/The Washington Post)

For the Torajan people of Indonesia, death is part of a spiritual journey: families keep the mummified remains of their deceased relatives in their homes for years – and traditionally invite them to join for lunch on a daily basis – before they are eventually buried. Here: Todeng died in 2009. A young relative of his, Sam, lights him a cigarette and changes his glasses. (Photo by Claudio Sieber Photography/The Guardian)

A freediver uses weights, yoga and camera tricks to create the illusion of walking underwater for a film which took three years to shoot and was completed in 2013 in El Hierro, Canary Islands. Like a scene from a Hollywood science-fiction movie, this trick footage shows a man apparently walking on water. The underwater film was shot by biologist Armiche Ramos and brothers Armando and Francisco del Rosario, who used their expertise in freediving to create the illusion. No computer graphics were involved in the production, with the team relying solely on their own skills – and a few hidden secrets. (Photo by Ocean Brothers/Barcroft Media/ABACAPress)

Stormtrooper Jacob French is pictured on day 5 of his over 4,000 kilometre journey from Perth to Sydney approximately 25 kilometres from Mandurah on July 15, 2011 in Perth, Australia. French aims to walk 35-40 kilometres a day, 5 days a week, in full Stormtrooper costume until he reaches Sydney. French is walking to raise money for the Starlight Foundation - an organisation that aims to brighten the lives of ill and hostpitalised children in Australia. (Photo by Paul Kane/Getty Images)