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.
Anshun is a prefecture-level city in Guizhou province. Located in the central and western part of Guizhou Province, 90 kilometers away from Guiyang, the capital of Guizhou Province. Located in the watershed of the Wujiang River Basin of the Yangtze River system and the Beipanjiang River Basin of the Pearl River system, it is a typical concentrated area of karst landforms in the world. Anshun is known as "the hometown of Chinese Waterfall", "hometown of Tunpu Culture", "hometown of Batik" and "Show of the West". It is an excellent tourist city in China, an open city for Class A tourism in China, and the only one in the country to "deepen reform, promote the symbiosis and prosperity of various economic sectors, and accelerate development". Reform pilot area, civil aviation industry national high-tech industrial base, Guizhou provincial historical and cultural city It is the "special economic zone for speeding up the development of Guizhou". In 2009, it is the top ten leisure cities with Chinese characteristics, the preferred area for karst scenery tourism in the world, and the six golden tourism in the country.