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.
Shanwei City is located on the southeast coast of Guangdong Province, bordering Jieyang City to the east, Huilai County to the east, Huizhou City to the west, Huidong County to the west, Heyuan City to the north, Zijin County to the north, and the South China Sea to the south. The total area is 5271 square kilometers. It has jurisdiction over 1 city, 2 counties and 3 districts, such as urban area, Haifeng County, Lufeng City, Luhe County, Honghai Bay Economic Development Experimental Zone and overseas Chinese Management Zone, with a total population of more than 3.3 million. There are 93 islands, 12 ports and 3 sea lakes in the sea area of Shanwei City. Shanwei Port is a natural deep-water port and the first-class coastal open port in the country. The inland topography of the area is dominated by mountains and hills, and there are many plains and hills along the coast. Hai Lufeng Revolutionary Base is one of the 13 revolutionary base areas in China. Shanwei is the meeting place of Chaoshan culture, Minnan culture, Guangfu culture and Hakka culture.