A mesa is an isolated, flat-topped elevation, ridge or hill, which is bounded from all sides by steep escarpments and stands distinctly above a surrounding plain. Mesas characteristically consist of flat-lying soft sedimentary rocks capped by a more resistant layer or layers of harder rock, e.g. shales overlain by sandstones. The resistant layer acts as a caprock that forms the flat summit of a mesa. The caprock can consist of either sedimentary rocks such as sandstone and limestone; dissected lava flows; or a deeply eroded duricrust. Unlike plateau, whose usage does not imply horizontal layers of bedrock, e.g. Tibetan Plateau, the term mesa applies exclusively to the landforms built of flat-lying strata. Instead, flat-topped plateaus are specifically known as tablelands.
Chengdong District of Xining City is located in the east of Xining City, the capital of Qinghai Province, in the lower reaches of Xining section of Huangshui River, bordering Ping'an District in the east, Huangzhong County in the south, Huzhong County in the west and Huzhu County in the north, which is the east gate of Xining City. It has jurisdiction over 1 town, 20 administrative villages and 12 community public service centers. The total population of the region is 325500, of which 106200 are ethnic minorities (about 89000 Hui), accounting for 34% of the total population. The area covers an area of 114 square kilometers. Xining Dongguan Mosque, Ma Bufang residence and other provincial key scenic spots and tourist attractions are in the area, and with the development of tourism, minority handicrafts, religious articles, national costumes and other popular tourism products and souvenirs. In December 2018, confirmed by the Ministry of Civil Affairs