Mongolian Buddhism: Ruins of the destroyed monastery of Ongiin Khiid. Reports indicate that in the 1920s there were over 112,000 Mongolian Buddhist monks, representing more than 13 percent of Mongolia's overall population. By the 1940s, nearly every monk was either dead or had apostatised. As late as 1934, the communist party counted 843 major Buddhist centers, about 3,000 temples of various sizes, and nearly 6,000 associated buildings, which usually were the only fixed structures in a world of yurts. By the late 1940s, one monastery, Gandan Monastery, with a community of 100 monks, remained open in Ulaanbaatar. It was the country's sole surviving monastery and was more for international display than functionality. A few of the old monasteries survived as museums, and Gandan served as a living museum and a tourist attraction. Public Domain image by Bouette. (Photo by: Bouette/Pictures From History/Universal Images Group via Getty Images)