General view of Chilean Calbuco volcano from Puerto Montt, located at 1000 km southern Santiago de Chile, Chile, 22 April 2015. Due to the eruption of the volcano with a smoke column 20 km high, authorities declared a red alert and ordered the evacuation of around 1500 inhabitants of Ensenada, Alerce, Colonia Río Sur and Correntoso towns. (Photo by Alex Vidal Brecas/EPA)

A Flemish demonstrator, one of thousands who gathered for a march through Brussels to protest against what the Flemings call their subjucation by the French-speaking Walloons, draws back as he is jeered by a crowd of Walloons on the pavement in a Brussels Street, on October 14, 1962. The Flemish demonstrators clashed with Walloon counter demonstrators as riot police sought to maintain order. The Flemings claim that although they form 60% of the population in Belgium, they are inadequately represented in the government, and they say, the Walloons get most of the top jobs in the armed forces and the diplomatic service. (Photo by AP Photo)

People affected by Hurricane Maria bathe in water piped from a creek in the mountains, in Naranjito, Puerto Rico, Thursday, September 28, 2017. Residents of the area drive to the pipes to bathe because they were left without water supplies by the damage caused by Hurricane Maria. The pipe was set up by a neighbor who ran it from a creek in his property to the side of the road in order to help those left without water. (Photo by Ramon Espinosa/AP Photo)

Artist Ted Harrison makes final adjustments to his artwork created with poppies on the floor of St. Paul's Cathedral on November 10, 2011 in London, England. Mr. Harrison created the work on a 30 foot disc under the main dome of the cathedral with the intention of drawing attention to the 250,000 children worldwide currently under military orders. (Photo by Peter Macdiarmid/Getty Images)

Boys play football in a shantytown of Olinda, about 18 km from Recife in northeastern Brazil, on June 18, 2013 as the FIFA Confederations Cup Brazil 2013 football tournament is being held in the country. The historic centre of Olinda is listed as an UNESCO World Heritage Site. (Photo by Yasuyoshi Chiba/AFP Photo)

The Stone Forest or Shilin is a notable set of limestone formations located in Shilin Yi Autonomous County, Yunnan Province, People's Republic of China, near Shilin approximately 120 km (75 mi) from the provincial capital Kunming. The tall rocks seem to emanate from the ground in the manner of stalagmites, with many looking like petrified trees thereby creating the illusion of a forest made of stone. Since 2007, two parts of the site, the Naigu Stone Forest (乃古石林) and Suogeyi Village (所各邑村), have been UNESCO World Heritage Sites as part of the South China Karst.

Young men play basketball on an improvised court wedged between a construction site and the shells of once grand colonial homes in Havana, July 20, 2015. As much as the young in Cuba welcome political opening and economic reform, such changes are unlikely to filter down to their lives anytime soon. (Photo by Meridith Kohut/The New York Times)