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.
Yuxi City, a prefecture-level city under the jurisdiction of Yunnan Province, is located in the middle of Yunnan Province, with geographical coordinates between 23 °19 °N, 24 °53'N and 101 °16 °E, 103 °09'E. It borders Kunming, the provincial capital in the north, Puer City in the southwest, Honghe Hani and Yi Autonomous Prefecture in the southeast and Chuxiong Yi Autonomous Prefecture in the northwest, with a total area of 15285 square kilometers. The topography of Yuxi is high in the northwest and low in the southeast, with staggered distribution of mountains, valleys, plateaus and basins, with a maximum horizontal distance of 172km and a maximum vertical distance of 163.5 km. Most of the area is 1,500 meters above sea level. The annual average temperature is 16.4 ℃, the climate is three-dimensional and diverse, there is no severe cold in winter, there is no heat in summer, the four seasons are like spring, dry and wet. Yuxi is the hometown of Nie er, the hometown of clouds and smoke, the hometown of lanterns and the water town of the plateau.