In this March 12, 2015 photo, a man tours a graffiti exhibition at the Museum of Modern Art, in Bogota, Colombia. The city-run museum recently held an exhibition highlighting the work of Bogota street artists who go by aliases such as Joems and the MonsTruacioN collective. (Photo by Fernando Vergara/AP Photo)

Star trails form over the Memorial House of the Bulgarian Communist Party on mount Buzludzha in this long exposure picture taken on September 12, 2014. The monument was officially opened in 1981 by the Bulgarian Communist regime to mark 100 years of the set up of an organised Socialist movement, a predecessor of the Bulgarian Communist Party. The monument, no longer maintained by the Bulgarian government after the fall of the Communist regime in 1989, is now abandoned and vandalized. (Photo by Stoyan Nenov/Reuters)

A visitor poses with artist Joyce Pensato's artwork “Mickey for Micky” at the Frieze Art Fair in London, October 14, 2014. (Photo by Luke MacGregor/Reuters)

Rag pickers collect recyclable material at a garbage dump in New Delhi November 19, 2014. (Photo by Ahmad Masood/Reuters)

A faithful prays during the Divine Liturgy by Pope Francis at the apostolic Cathedral in Etchmiadzin, Armenia, June 26, 2016. (Photo by David Mdzinarishvili/Reuters)

A woman looks across as a gay parade participant poses for pictures during Gay Pride parade in Madrid, Spain, Saturday, July 2, 2016. Hundreds of thousands of people defied high temperatures and relative security concerns and turned out in Madrid to march in Saturday's LGTB Pride parade, one of the biggest in Europe, along the streets of the Spanish capital, just three weeks after members of the gay, lesbian, bisexual and transgender community were tragically victimized in a shooting massacre at a United States nightclub. (Photo by Daniel Ochoa de Olza/AP Photo)

Maria Menounos and Derek Hough sit courtside as the Celtics play the Lakers in Los Angeles, March 2012. (Photo by Lucy Nicholson/Reuters)

North Koreans wave as Hughes MD-500 helicopters fly past during an aerial display on Saturday, September 24, 2016, in Wonsan, North Korea. North Korea on Saturday opened an air festival featuring sky diving, demonstrations by its air force and lots of beer to promote a newly renovated and upgraded commercial airport in the coastal city of Wonsan that it hopes will draw for foreign tourists. (Photo by Wong Maye-E/AP Photo)