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.
Huangmei County, which belongs to Huanggang City, Hubei Province, is located on the north bank of the middle reaches of the Yangtze River, on the southern edge of the tail of the Dabie Mountains; the terrain is high in the north and low in the south; it belongs to the subtropical monsoon climate; the total area of the county is 1701 square kilometers. As of 2018, Huangmei County has jurisdiction over 12 towns, 4 townships and one scenic spot with a total population of 1.0073 million. Huangmei County was founded in the 18th year of Emperor Kaihuang of the Sui Dynasty (598 years). Huangmei County is named for Huangmeishan and Huangmeishui, which has a history of more than 1400 years. Huangmei County is located in Wu Tou and Chuwei, where Jingchu culture and Wu Yue culture mingle, forming a unique Huangmei culture. Huangmei County is located in central China, bordering Hubei, Jiangxi and Anhui provinces, facing Susong in the east, Jiujiang in the south, Wu acupoint in the west, and Lianchun in the north. The Beijing-Kowloon and he-Kowloon railways meet here, and the Shanghai-Chongqing, Fuyin Expressway and Yangtze River waterway cross the border.