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.
Bo (b ó) Zhou, referred to as Bo, was called "qiao City" in ancient times, and it was a prefecture-level city in Anhui Province. Located in the northwest of Anhui Province, located at the southern end of the North China Plain, 330km away from the provincial capital Hefei, located in longitude 115o 53km east, latitude 32 °51m "35 °05km, bordering Henan Province in the west and north, Fuyang City in the southwest, Huaibei City and Bengbu City in the east, and Huainan City in the southeast, covering an area of 8374 square kilometers. Bozhou is a famous national historical and cultural city. Human beings have been active here since the Neolithic Age, and it is one of the birthplaces of the ancient culture of the Chinese nation. In the Yan-Huang era, Emperor Kui (the great-grandson of the Yellow Emperor) took the place of the Emperor, all in Bo. Shang Cheng Tang destroyed Xia and established the Shang Dynasty in Bolidu 190 years. Since the Qin Dynasty set up Yixian County, there have been more and more dynasties.