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.
Lianshan Zhuang Yao Autonomous County, which belongs to Qingyuan City, Guangdong Province, is located in the Mengzhu Mountains, one of the Wuling Mountains in Nanling, and in the joint of Guangdong, Hunan and Guangxi provinces (regions). Babu District, Hezhou City, Guangxi Zhuang Autonomous region in the west, and Jianghua Yao Autonomous County in Hunan Province in the north, with numerous peaks, vertical and horizontal streams, and steep terrain. 87% of the total area of the county is mountainous. In ancient times, it is known as "nine mountains, half water and half land." after years of afforestation, the forest coverage rate reached 86.2% in 2014, ranking first in Guangdong. It is rich in native products such as Shatian pomelo, big meat ginger, rosin, Huaishan, winter mushrooms, tea oil, honey, fragrant japonica, bamboo shoots and so on, among which big meat ginger is known as "the hometown of Guangdong ginger". The autonomous county has jurisdiction over seven towns of Yoshida, Taibao, Wedong, Yonghe, Futang, Xiao Sanjiang, Shangshuai and three agriculture and forestry.