Gers, traditional Mongolian tents, are seen on a hill in an area known as a ger district in Ulan Bator June 26, 2013. Approximately 60 percent of the population of Ulan Bator live in settlements known as ger districts and in many cases residents have limited access to basic services such as water and sanitation. According to a 2010 National Population Center census, every year between thirty and forty thousand people migrate from the countryside to the capital Ulan Bator. Ger districts in the city have been expanding rapidly in recent years. Mongolia is the world's least densely populated country, with 2.8 million people spread across an area around three times the size of France. (Photo by Carlos Barria/Reuters)

Jewish children in fancy dress during the annual Jewish holiday of Purim on March 12, 2017 in London, England. Purim is celebrated by Jewish communities around the world with parades and costume parties. Purim commemorates the defeat of Haman, the advisor to the Persian king, and his plot to massacre the Jewish people, 2,500 years ago, as recorded in the biblical book of Esther. (Photo by Dan Kitwood/Getty Images)

Hindu women perform a ritual known as Aarti around a Shivling (a symbol of Lord Shiva) on the last day of Jaya Parvati Vrat festival in Ahmedabad, India, July 10, 2017. (Photo by Amit Dave/Reuters)

Afghan policemen take position at the site of a suicide attack followed by a clash between Afghan forces and insurgents after an attack on a Shi'ite Muslim mosque in Kabul, Afghanistan on Friday, August 25, 2017. Gunmen stormed a Shiite mosque in the Afghan capital while worshippers were at Friday prayers, setting off an explosion that killed a security guard outside and pushing into the shrine, officials said. (Photo by Omar Sobhani/Reuters)

A performer poses during celebrations after Rahul Gandhi, newly elected president of India's main opposition Congress party, took charge as the president during a ceremony outside the party's headquarters in New Delhi, India, December 16, 2017. (Photo by Altaf Hussain/Reuters)

Hindu devotees watch as a 12 meter (40 feet) high statue of Hindu monkey-god Hanuman is washed during Hanuman Jayanti, the birthday of Lord Hanuman in Hyderabad, India, Friday, April 22, 2016. Hanuman is one of the most popular gods in the crowded pantheon of Hindu deities, and devout Hindus ascribe great strength and valor to him. (Photo by Mahesh Kumar A./AP Photo)

In this July 11, 2016 photo, a young, masked drug trafficker poses for photos holding his guns at a slum in Rio de Janeiro, Brazil. Teenagers openly tote guns while they work as guards, lookouts and distributors for drug lords operating just a few miles from where hundreds of thousands and tourists and athletes will be for the Aug. 5-21 Olympic Games. (Photo by Felipe Dana/AP Photo)

A visitor jumps for a photograph on the world's highest and longest glass-bottomed bridge above a valley in Zhangjiajie in China's Hunan Province on August 21, 2016. The bridge, which opened to the public on a trial basis on Saturday, spans 430 meters (1,410 feet) and rises about 300 meters (984 feet) above a valley in a scenic zone, making it the world's highest and longest glass-bottomed bridge according to Chinese state media. (Photo by Fred Dufour/AFP Photo)