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.
Renhuai is located in the northwest of Guizhou Province, belonging to Zunyi City, Guizhou Province, the middle reaches of the Chishui River, the north side of the western section of the Dalou Mountains, and the back of Zunyi, which is a typical mountain area of the transition from the Yunnan-Guizhou Plateau to the Sichuan Basin. It is the connecting point between the economic zone of northern Guizhou and the economic zone of southern Sichuan. It is the place where the Red Army fought in the long March "four crossing Chishui". It is the hometown of Maotai Liquor. In July 2004, it was officially recognized as the "wine capital of China". The city covers an area of 1788 square kilometers and has jurisdiction over 14 towns, 1 township, 5 subdistrict offices, 149 village committees and 22 community neighborhood committees. It is inhabited by 9 ethnic groups, including Han, Miao, Buyi, Gelo, Yi and Bai, with a total population of 640000. The existing cultivated land is 27713.3 hectares, including 9921 hectares of farmland and 17792.2 hectares of soil. A mountain with few territories and many people