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.
Hegang City, a prefecture-level city in Heilongjiang Province, is located in the northeast of Heilongjiang Province, facing Russia across Heilongjiang River to the north, bordering Songhua River and Jiamusi in the southeast, and Xiaoxinganling in Xiping adjacent to Yichun. It is located in the "Golden Triangle" area surrounded by "two rivers and one ridge" in Heilongjiang, Songhua River and Xiaoxing'an Mountains, with a total area of 14684 square kilometers and has jurisdiction over 2 counties and 6 districts. The resident population is 995000 in 2018. Hegang is rich in tourism resources, with Dajie River, forest, ice and snow, wetlands, agriculture, mines, stone forest, the original ecology is well preserved. The three Gorges is one of the top ten tourist attractions in Heilongjiang Province. There are three national primeval forest parks, the National Mine Geopark, as well as Heilongjiang Valley Museum, famous Mountain Tourism Town, Taipingou Golden Ancient Town, Jindingshan Stone Forest and Reed Field.