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.
Linwei District of Weinan City is located in the east of Guanzhong Plain, Shaanxi Province, which is called "Xiagu", "Lotus Spoon", "Nanxinfeng" and "Lingyuan" in ancient times. It is the seat of Weinan municipal party committee and municipal government, and the meeting point of Weinan's politics, economy, culture, transportation, trade, logistics center and decision-making exchange and management of the whole city. it is one of the most important birthplaces of Chinese civilization. The region has jurisdiction over 28 towns (offices), with a resident population of 900100 (2017) and a registered household population of 1.0261 million (2016). By the end of 2015, the construction area of the central city of Linwei District has reached 71 square kilometers, and the population of the built-up area of the central urban area has reached 600000. It is the largest city in the Golden Triangle of the Yellow River in Shanxi, Shaanxi and Henan and a regional central city in the east of Guanzhong. With a total area of 1221 square kilometers, as early as the Tang Dynasty