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)

Viking re-enactors representing the rival armies of the Vikings and Anglo-Saxons skirmish near Clifford’s Tower during the Jorvik Viking Festival on February 23, 2019 in York, England. The annual Jorvik Viking Festival held in York is recognised as the largest event of its kind in Europe. This year the festival remembers the role that the Viking women played during those turbulent times. (Photo by Christopher Thomond/The Guardian)

A woman takes a photo on her mobile phone of a tiger during the media preview of Vivid Sydney at Taronga Zoo on May 19, 2019 in Sydney, Australia. An illuminated trail of almost 300 lit lanterns of endangered species will glow every night at the zoo during Vivid Sydney which runs from May 24 throughout Sydney with hundreds of lit buildings and exhibits which attract hundreds of thousands of visitors each year. (Photo by James D. Morgan/Getty Images)

A landscape photographer turned the camera on himself to take a set of incredible selfie while visiting some of the world's most beautiful destinations. Paul Zizka, 39, from Alberta, Canada, has been a photographer for nine years, and thought that featuring in his own pictures would emphasize the nature surrounding him and create a more unique shot. Here: Lake Minnewanka, Banff National Park, Alberta, Canada. (Photo by Paul Zizka/Caters News Agency)

Indian ivory furniture legs in the shape of a goddess from the first century AD are displayed in the 'Afghanistan Crossroads of the Ancient World' exhibition at The British Museum on March 1, 2011 in London, England. Displaying treasures that were in great danger during the years of civil war and Taliban rule, these surviving artifacts reveal Afghanistan's ancient culture, its fragility and its remarkable place in world history. The exhibition opens to the public on March 3 and runs until July 3, 2011. (Photo by Peter Macdiarmid/Getty Images). LONDON, ENGLAND – MARCH 01

In this artist's impression supplied by the ESO (European Southern Observatory) on April 25, 2007, the planetary system around the red dwarf, Gliese 581, is pictured showing what astronomers believe is the most earth like planet found outside our solar system to date. Using the ESO 3.6-m telescope in Chile, astronomers have uncovered the planet which could have water running on its surface. The planet orbits the faint star Gliese 581, which is 20.5 light-years away in the constellation Libra. (Photo by ESO via Getty Images)

A Dartmoor Hill pony foal runs on the moor on Dartmoor on May 17, 2011 in Princetown England. Although a tourist attraction, especially during the foaling season and often seen as part of the landscape of Dartmoor, many ponies face an uncertain future due to unsustainable breeding and their falling market values. The charity South West Equine Protection estimates that last year 1500 ponies were slaughtered – with many being sold for lion meat to nearby zoos. Along with other equine charities, they are calling for the removal of stallions from the moor to bring numbers down to sustainable levels. (Photo by Matt Cardy/Getty Images)