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.
Panshan County, under the jurisdiction of Panjin City, Liaoning Province, is located in the north of Panjin City, the lower reaches of the Liao River and the coast of the Bohai Sea. It faces Taian County and Haicheng in the east, Panjin City and Dawa District in the south, Linghai City in Jinzhou City in the west and Beizhen City in Jinzhou City in the north. As of 2013, Panshan County covers an area of 1735 square kilometers and has jurisdiction over 10 towns and 117 administrative villages with a total population of 225800. In 2013, the GDP of Panshan County reached 19.7 billion yuan, the investment in fixed assets of the whole society reached 19.1 billion yuan, the public budget income reached 2.23 billion yuan, and the per capita disposable income of residents reached 16100 yuan, an increase of 25.3 percent. Panshan County is "the top ten counties with comprehensive strength in Liaoning Province", "the first county in Chinese river crab industry", and "provincial leisure agriculture and rural areas in Liaoning Province".