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.
Lazi County is located in the southwest of Tibet Autonomous region, in the middle of Xigaze City, and in the westernmost part of Nianqing Tanggula Mountain. Between 87 °24 degrees east longitude 88 °21 'east longitude, 28 °47 degrees north latitude and 29 °37' north latitude. It connects Sakya County to the east, Dingri County to the southwest, Angren County to the west and Xietongmen County to the north. The county government is 150 kilometers east from Xigaze City and 276 kilometers from Xigaze to Lhasa. The county is about 69 kilometers from east to west and 98 kilometers from north to south, with a total area of 4505 square kilometers. Lazi County has jurisdiction over 9 townships and 2 towns (105 natural villages) with a total population of 52616 (2011). On December 7, 2016, Lazi County was listed as the third batch of national comprehensive pilot areas for new urbanization. On January 9, 2019, he was selected as the 2018 THI 2020 by virtue of Lazidi Harmony.