Areas of coastal marshland formed an important and distinctive part of the landscape of Roman Britain, and current work is showing that different wetlands were utilised in very different ways. Some areas, for example in Essex and Kent, were simply exploited for their natural resources to produce salt and support seasonal grazing. Parts of Fenland were also used in this way, though the higher coastal siltlands were modified through the creation of drainage systems in order to improve agricultural opportunities within a landscape that was still liable to tidal flooding. A third strategy towards wetland exploitation is reclamation: a major transformation of the natural environment, involving the construction of a sea wall along the coast to keep tidal waters out and a system of drainage ditches cut into the surface of the former saltmarsh to lower the water table and remove surface run-off from the surrounding uplands.