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.
Alar, a county-level city directly under the jurisdiction of the Xinjiang Uygur Autonomous region, implements the integrated management system with the first Division of the Xinjiang production and Construction Corps, which is managed by the Xinjiang production and Construction Corps. It extends from the southern foot of Tianshan Mountain to the north of Taklimakan Desert in the south, Shaya County in the east, Keping County in the west, Aksu River, Tarim River, Tellan River and Duolang River in the north, and Xinhe County in the northeast. The distance between east and west is 281 km and that between north and south is 180 km. Bordering with Kyrgyzstan, Tajikistan and Kazakhstan, and close to Pakistan and India, it has rich border ports and border trade resources. Alar means "converge, converge" in Mongolian. The geographical coordinates are 80 °30'E to 81 °58 °E and 40 °22'to 40 °57'N. In 2016, Alar was killed