SIEM REAP, CAMBODIA - JANUARY 13: A young monk sits in front of the Angkor Wat temple reflected on a lake on January 1, 2016 in Siem Riep, Cambodia. Angkor was the capital city of Khmer Empire, which flourished from approximately the 9th to 15th centuries. Angkor was a megacity supporting at least 0.1% of the global population during 1010-1220. The city houses the magnificent Angkor Wat, one of Cambodia's popular tourist attractions. (Photo by Xaume Olleros/Getty Images)