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.
Honghe County is located in the south of Yunnan Province, on the south bank of the upper reaches of the Honghe River, belonging to Honghe Hani and Yi Autonomous Prefecture. It is located between longitude 101 °49 & #39;-102 °37 & #39;, 23 °05 & #39;-23 °27 & #39;, bordering Yuanyang County and Luchun County in the east and south, facing the Red River in Shiping County in the north, Mojiang County in Simao City in the west and Yuanjiang County in Yuxi City in the northwest. The maximum distance from east to west is 81 kilometers, the widest from north to south is 40 kilometers, and the land area is 2057 square kilometers. The total population is 296500 (2010). The county seat is stationed in Luisa town. There are Hani, Yi, Dai, Yao and other ethnic minorities living in the territory, and the minority population accounts for the total population of Honghe County.