A military band prepares to play the national anthems before Cuban President Raul Castro welcomes U.S. President Barack Obama at the Palacio de la Revolucion in Havana March 21, 2016. Barack Obama on Sunday became the first US president in 88 years to visit Cuba, touching down in Havana for a landmark trip aimed at ending decades of Cold War animosity. (Photo by Jonathan Ernst/Reuters)

A man suffering from mental illness sits chained on a bed in his room inside his family home in Curug Sulanjana village in Serang, Banten province, Indonesia March 23, 2016. In a programme launched this year, Indonesia sends teams of workers into often-remote hamlets to help free patients kept in chains and ensure they get the medical treatment they need. (Photo by Reuters/Beawiharta)

The Andromeda Galaxy, the nearest major galaxy to the Milky Way, can be seen shining above a remote village in Switzerland. The cinematic images convey the beauty of the galaxy gleaming above the picturesque Swiss mountains. Photographer Sandro Casutt took the amazing snaps in different seasons throughout the year, from his home valley of Vals, Switzerland. Here: A view of the sky from the Zervreila Mountain Lagoon in Switzerland. (Photo by Sandro Casutt/Caters News)

Dave Zdanowicz, a prominent landscape photographer from the north of England, here shares his favourite shots from this year. This series brings together photos from January to last month, displaying the fine range of English seasons he has documented. Here: Misty sunrise at Winnat's Pass, Derbyshire on August 26, 2016. (Photo by Dave Zdanowicz/Rex Features/Shutterstock)

In this photo taken on Friday, July 14, 2017, a student at a paramilitary camp for children calls the rank to attention outside Kiev, Ukraine. As the deadly conflict in eastern Ukraine entered its third year, some parents in Ukraine are anxious to make sure their children are ready to fight it, instead of swimming and playing volleyball. (Photo by Efrem Lukatsky/AP Photo)

The 6th Siberian Tattoo Festival at Podzemka Loft Park in Novosibirsk, Russia on August 20, 2017. Tattoo lovers have been showing off their impressive inkings at annual conventions in LA and Russia this weekend. This year marks the sixth Siberian Tattoo Festival in Novosibirsk, Russia, while stateside tattoo fanatics have been celebrating all things body-art at the LA Tattoo Convention in Long Beach, California. (Photo by Kirill Kukhmar/TASS)

Elise Graham takes part in the World Bog Snorkelling Championships 2017 with a rubber duck on her back on August 27, 2017 in Llanwrtyd Wells, Wales. The competition draws competitors from all over the world and is now in its 32nd year. (Photo by Matthew Horwood/Getty Images)

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)