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.
Renshou County, which belongs to Meishan City, Sichuan Province, is located 34.32 km southeast of Dongpo District, Meishan City, 50 km north of Chengdu, 80 km south of Leshan and 70 km east of Ziyang. It has jurisdiction over 32 towns and 28 townships, covering an area of 2606.36 square kilometers (of which, 9 villages and towns are managed by Meishan District, Tianfu New District). In 2018, the registered population is 1.54 million and the resident population is 1.201 million. Renshou is the first batch of pilot counties in Sichuan Province to expand power, advanced county economic development, top 10 hilly economic counties, demonstration counties with strong industrial strength, pilot counties for comprehensive reform in small and medium-sized cities, and radiation counties in Tianfu New District, Sichuan. Renshou is 70 kilometers away from Chengdu Shuangliu International Airport and 30 kilometers away from Chengdu Tianfu International Airport. The 180-meter-wide central axis of a world-class city-- Tianfu Avenue.