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.
Guzhang County, which belongs to Xiangxi Tujia and Miao Autonomous Prefecture, is located in the west of Hunan Province and the middle of Xiangxi Autonomous Prefecture. Guyang Town is the seat of the county, which reaches Baojing in the west, Yuanling in the east, Jishou and Luxi in the south, and Yongshun in the north. With a total area of 1286 square kilometers, it has jurisdiction over seven townships and five towns, with a total population of 144100 (2016), of which ethnic minorities account for 76.9 per cent. Guzhang County has an excellent ecological environment, and the green rate of trees is as high as 80.46%. It is known as "the hometown of forestry, famous tea, weightlifting, singing and dancing". Guzhang County is the hometown of singers Song Zuying and he Jiguang, with unique characteristics such as Tujia Maogus, waving dance, Miao encouragement and so on. There are World Geological sites-Guzhang Golden Nail, National Geopark-Red Stone Forest, National Nature Reserve-