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.
Kaifeng, known as Bianzhou and Bianliang in ancient times, is a prefecture-level city in Henan Province. It is a cultural tourism city approved by the State Council and one of the central cities in the core area of the Central Plains urban agglomeration. By 2018, the city had jurisdiction over five districts and four counties, with a total area of 6266 square kilometers, a built-up area of 129.93 square kilometers, a resident population of 4.5649 million, and an urban population of 2.23 million, with a urbanization rate of 48.9%. Kaifeng is located in the hinterland of the Central Plains, the shore of the Yellow River, adjacent to Zhengzhou in the west. Kaifeng Free Trade Zone is one of the three major free trade pilot zones in China (Henan). It is the first batch of famous national historical and cultural cities with a history of more than 4100 years, including Xia Dynasty, Wei State in the warring States period, Hou Liang, Hou Jin, Hou Han, Hou Zhou and Song Dynasty in the five dynasties.