East Asia is the eastern subregion of Asia, which can be defined in either geographical or ethno-cultural terms. Culturally, China, Japan, Korea, and Vietnam are commonly seen as being encompassed by cultural East Asia (East Asian cultural sphere). Geographically and geopolitically, the region constitutes China, Hong Kong, Macau, Taiwan, Japan, Mongolia, North Korea, and South Korea.The region was the cradle of various ancient civilizations such as ancient China, ancient Japan, ancient Korea, and the Mongol Empire. East Asia was one of the cradles of world civilization, with China, an ancient East Asian civilization being one of the earliest cradles of civilization in human history. For thousands of years, China largely influenced East Asia as it was principally the leading civilization in the region exerting its enormous prestige and influence on its neighbors. Historically, societies in East Asia have been part of the Chinese cultural sphere, and East Asian vocabulary and scripts are often derived from Classical Chinese and Chinese script. The Chinese calendar preserves traditional East Asian culture and serves as the root to which many other East Asian calendars are derived from. Major religions in East Asia include Buddhism (mostly Mahayana), Confucianism and Neo-Confucianism, Taoism, Ancestral worship, and Chinese folk religion in Greater China, Buddhism and Shintoism in Japan, and Christianity, Buddhism, and Sindoism in Korea. Shamanism is also prevalent among Mongols and other indigenous populations of northern East Asia such as the Manchus.East Asians comprise around 1.6 billion people, making up about 38% of the population in Continental Asia and 22% of the global population. The region is home to major world metropolises such as Beijing, Hong Kong, Seoul, Shanghai, Taipei, and Tokyo. Although the coastal and riparian areas of the region form one of the world's most populated places, the population in Mongolia and Western China, both landlocked areas, is very sparsely distributed, with Mongolia having the lowest population density of any sovereign state. The overall population density of the region is 133 inhabitants per square kilometre (340/sq mi), about three times the world average of 45/km2 (120/sq mi).