s*x workers, wearing decorative skull masks, march through the streets in downtown Mexico City, Friday, October 28, 2016. The women march with candles to an altar dedicated to their departed colleagues, many who died violently at the hands of their customers. This annual procession, tied to the Day of the Dead festivities, has taken place for more than 20 years. (Photo by Eduardo Verdugo/AP Photo)

A citizen rides in smog on December 20, 2016 in Jinan, Shandong Province of China. Air quality index (AQI) readings exceeded 400 and some schools have suspended classes in Jinan. (Photo by VCG/VCG via Getty Images)

A rag-and-bone woman stands next to carriages of a coal train outside a coal mine of the state-owned Longmay Group on the outskirts of Jixi, in Heilongjiang province, China, October 22, 2015. (Photo by Jason Lee/Reuters)

Competitors take part in the Red Bull Crashed Ice Cross Downhill World Championship in Marseille, France, January 14, 2017. (Photo by Jean-Paul Pelissier/Reuters)

In this Thursday, March 17, 2016 photo, 33-year-old Palestinian clown doctor Alaa Miqdad, left, entertains 3-year-old patient Yaqin Shawaf, who suffers from dialysis, in the department of kidney diseases at Al-Rantisi children's hospital in Gaza City. (Photo by Adel Hana/AP Photo)

An Israeli policeman prevents a Palestinian man from entering the compound which houses al-Aqsa mosque, known by Muslims as the Noble Sanctuary and by Jews as the Temple Mount, in Jerusalem's Old City September 28, 2015. (Photo by Ammar Awad/Reuters)

Built for over a million people, the city of Ordos was designed to be the crowning glory of Inner Mongolia. Doomed to incompletion however, this futuristic metropolis now rises empty out of the deserts of northern China. Only 2% of its buildings were ever filled; the rest has largely been left to decay, abandoned mid-construction, earning Ordos the title of China's Ghost City.

A man wearing a Pikachu hat, a character from Pokemon, plays Pokemon Go during a gathering to celebrate “Pokemon Day” in Mexico City, Mexico August 21, 2016. (Photo by Carlos Jasso/Reuters)