Compared with mountainous terrain, such as in the Andes or the Himalayas, Florida is almost featureless; but if Florida is studied without regard to other areas, many variations in the land surface can be seen. Coastal areas may be subdivided into barrier islands, Gulf coast estuaries (river mouth bays), swamps and marshes, lowlands, and the Florida Keys (limestone islands in a chain near the southern tip of the state). Swamps are poorly drained flatlands having a tree cover; in the coastal zone, this tree cover is commonly dominated by mangroves. Marshes are flatlands having poor drainage and basically a grass or low shrub cover. The coastal lowlands typically have better drainage than marshes and swamps. In addition, there are highlands and ridges, which stand well above adjacent areas, and which are well drained; upland plains, which are relatively featureless and not well drained; and transition areas. The transition areas are located between highlands and coastal lowlands and do not really have the characteristics of either.
This broad diversity within the state is complicated by smaller, more recent features, such as sinkholes, solutionÊlakes, and solutionÊmarshes (all made by dissolving part of the underlying limestone), sand dunes (built by the wind), and modern river deltas (within estuaries in the panhandle).
