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.
Hunan Province, referred to as Hunan, is one of the 23 provinces in China, bounded by 24 °38 degrees north latitude 30 °08 degrees north latitude, 108 °47 degrees east longitude, 114 °15 degrees east longitude, Jiangxi to the east, Chongqing and Guizhou to the west, Guangdong and Guangxi to the south, and Hubei to the north, with a total area of 211800 square kilometers. Hunan is located in the transitional zone from Yunnan-Guizhou Plateau to Jiangnan hills and Nanling Mountains to Jianghan Plain. Hunan is a horseshoe-shaped landform surrounded by mountains on three sides and opening to the north, which is composed of plains, basins, hills, mountains, rivers and lakes. Hunan is a subtropical monsoon climate across the Yangtze River and Pearl River systems. As of July 2019, Hunan Province has a total area of 211800 square kilometers and has jurisdiction over 13 prefecture-level cities and 1 autonomous prefecture. 36 municipal districts, 18 county-level cities, 61 counties and 7 autonomy