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.
Huanren Manchu Autonomous County, which belongs to Benxi City, Liaoning Province, is located in the eastern mountain area of Liaoning Province, connected with Ji'an City, Jilin Province in the east, Kuandian Manchu Autonomous County in Dandong City in the south, Benxi Manchu Autonomous County and Xinbin Manchu Autonomous County in Fushun City in the west, and Tonghua City in Jilin Province in the north, covering an area of 3547 square kilometers. Huan Renyuan lived in the new timer era (more than 6000 years ago), and belonged to the State of Yan during the warring States period; it was connected with Ji'an City in the east, Kuandian County in Dandong City in the south, Benxi County and Xinbin County in Fushun City in the west, and Tonghua City in Jilin Province in the north, 460km from Shenyang, 174km in Dandong City, 192km in Benxi City, 70km in Tonghua City and 159km in Jian City. Huanren Manchu Autonomous County has won many honors, Fenglin