Chongqing, Yu for short and known as the Mountain City, is a municipality directly under the Central Government of the P.R.C, a National Central City, a megacity as well as an important base of modern manufacturing and the integrated communication hub in Southwest China. As of 2018, the city had an area of 82,402 km² including the built-up area of 1,379 km², and a permanent population of 31.0179 million with the urban populace totaling 20.3159 million or 65.5%. Situated in West China, the upper reaches of the Yangtze River and the southwest of China's inland region, Chongqing, is the upper reaches' center of economy, finance, scientific innovation, shipping, and business logistics and one of China's logistics hub. The city is also considered as a key strategic fulcrum of the Western Development Strategy, an important junction between the B&R route and the Yangtze River Economic Belt, and an inland open-economic highland. By virtue of its picturesque sceneries, Chongqing is reputed as the City of Rivers, the City of Fog, and the City of Bridges and well-known as the Mountain City, and embraces such stunning landscape as the Three Gorges, Dazu Rock Carvings (a World Cultural Heritage Site), Wulong Karst (a World Natural Heritage Site), and Mount Jinfo in Nanchuan District. Chongqing is the place of origin of Hongyan Spirit and Bayu Culture, with the hotpot, stilt buildings and other elements exerting a far-reaching influence. Chongqing, historically famous as Bayu, was selected as the national capital three times and experienced four times of fortifications during the past more than 3 millennia.