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.
Leshan, a prefecture-level city under the jurisdiction of Sichuan Province, known as Jiazhou in ancient times, has the reputation of "Begonia fragrant country". Located in the middle of Sichuan Province, southwest of Sichuan Basin, the terrain is high in the southwest and low in the northeast, belonging to the subtropical climatic zone. Leshan is an important industrial city in Sichuan Province, a regional central city in the south of Chengdu Economic Zone, an important hub city, an important traffic node and port city in Chengdu-Chongqing urban agglomeration. Chengdu-Kunming Railway and Chengdu-Guizhou high-speed railway run through the whole territory. Leshan is a famous national historical and cultural city, the first batch of national open cities, national greening model cities, Chinese excellent tourist cities, national garden cities and national sanitary cities. Leshan has three world-class heritage sites-the World Natural and Cultural Heritage Mount Emei and Leshan Giant Buddha, the World Irrigation Engineering Heritage Dongfengyan, 15 scenic spots above the national 4A level, and 35 national A-level scenic spots. Cut off