Plateaus of Asia, areas of a highland consisting of flat terrain, that is raised sharply above the surrounding area on at least one side. Often one or more sides have deep hills. Plateaus can be formed by a number of processes, including upwelling of volcanic magma, extrusion of lava, and erosion by water and glaciers. Plateaus are classified according to their surrounding environment as intermontane, piedmont, or continental. A few plateaus may have a small flat top while others have wide ones.