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.
Weidu District is located in the hinterland of the Central Plains and the core radiation fortress of the Central Plains Economic Zone and Zhengzhou Airport Economic Comprehensive Experimental Zone. It is the central city of Xuchang City. It is the seat of Xuchang Municipal Committee and Municipal people's Government of the Communist Party of China. As of 2013, Weidu District has jurisdiction over 12 streets and 1 provincial industrial agglomeration area, 97 communities. It has more than 60 monuments of the three Kingdoms, such as the ancient city of Han and Wei, the Baling Bridge, the Spring and Autumn Tower, Cao Cao shooting Lutai, Cao Pi Dengji Zen Taiwan, and the divine doctor Hua Tuo's tomb. The second batch of water-saving society construction up to the standard county (district).