Dried and shrivelled corpses, some fully clothed and some in coffins, line the wall of a vault of the Pantheon Cemetery on the summit of Cerro del Trozado in Mexico. They were removed from the crypts because of non-payment of cemetery fees. The hot dry air stopped the bodies from rotting. Most of them were placed here between the turn of the century and WW I. (Photo by Three Lions/Getty Images). Circa 1955

Frander Arroyo, select wings of butterflies at Blue Morpho Butterfly House in Alajuela, Costa Rica, March 10, 2016. According to Arroyo, owner of Blue Morpho Butterfly House, he collects dead butterflies from his garden to mount as handicraft like earrings, necklaces, paintings and rings for export with prices ranging from $12 to $16 a piece. (Photo by Juan Carlos Ulate/Reuters)

Non-Hindus carry nets as they wait on the edge of the crater to catch offerings cast down by Hindus during the Kasodo ceremony at Mount Bromo, Probolinggo, Indonesia, August 12, 2014. The Kasodo ceremony is a way of Tengger Hindus to express their gratitude to God for good harvest and fortune. The offerings range from vegetables to chickens, from fruits to goats, from money to other valuables. (Photo by Fully Handoko/EPA)

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 The monument, no longer maintained by the Bulgarian government after the fall of the Communist regime in 1989, is now abandoned and vandalized.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)

Ultra- trailers compete at sunrise on September 2, 2017 in Courmayeur, Italy, during the 15 th edition of the Mount Blanc Ultra Trail (UTMB), a 170 km race around the Mont Blanc crossing France, Italy and Switzerland. The 15 th Ultra- Trail du Mont- Blanc (UTMB) is a mountain ultramarathon with numerous passages in high altitude (>2500 m) and in difficult weather conditions (night, wind, cold, rain or snow). (Photo by Jeff Pachoud/AFP Photo)

Tourists gather to watch Mount Agung at Amed beach in Karangasem on Indonesia' s resort island of Bali on November 30, 2017. Thousands of foreign tourists were expected to leave Bali by plane on November 30 following a nearly three- day airport shutdown sparked by a rumbling volcano on the Indonesian holiday island. (Photo by Juni Kriswanto/AFP Photo)

A painting of Chinese President Xi Jinping holding an umbrella is seen on the toilet wall in a guesthouse in Hong Kong December 30, 2014. Set up in a small apartment in the Causeway Bay shopping district, the guesthouse that gives what it calls “Umbrella Revolution Occupation Experience” charges guest HK$100 (US$13) a night to stay in a tent surrounded by pro-democracy banners, a cardboard cutout of President Xi Jinping holding a yellow umbrella, and serve toilet paper printed with the face of embattled leader of Hong Kong chief executive Leung Chun-ying. (Photo by Tyrone Siu/Reuters)

Students from Langata primary school run past riot police as they protest against a perimeter wall illegally erected by a private developer around their school playground in Kenya's capital Nairobi January 19, 2015. Riot police used teargas to disperse students at a school in Nairobi as the children protested against the potential loss of their playground. The playground was fenced off in December, during the school holidays, by a prominent developer who also claims ownership of the land. The title to the contested site is said to be in the name of Airport View Housing Limited, according to local media, with plans to use the space to build a parking lot for a hotel. (Photo by Thomas Mukoya/Reuters)