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.
Dingan County is located in the central northeast of Hainan Island, longitude 110o 7km east, latitude 19 °13km, north latitude 19 °13km, Wenchang City to the east, Chengmai County to the west, Qionghai City to the southeast, Tunchang County to the southwest, across the river to the north and Qiongshan District of Haikou City to the north, 45.50km from east to west, 68km from north to south, 251.50 km from north to south, and 251.50 km from north to south. The population of the county is 310000, covering an area of 1189 square kilometers. Ding'an County has the geographical location of facing the air and the sea, and has the advantages of developing tropical high-efficiency agriculture, high-tech industry, warehousing industry, commercial and residential industry and trade projects. It is the birthplace of Qiong Opera and has a large number of celebrities. Known as the folk spread of "no stable opera troupe", known as Hainan's "hometown of Qiongju Opera", it was awarded by the Ministry of Culture in November 2011.