Where there is a marked change of level and it is necessary to retain the earth there is a choice of structures, as follows:
The criteria governing the choice of retaining structure depends on the sort of access proposed, the materials, and the steepness of the level change. Construction methods can vary depending on cost and materials available. Steps, ramped steps and ramps permit access, and steps can also be used for sitting on. Ramps are necessary in order to permit disabled access. Long steps are an alternative to retaining walls. They do not divide a space and can have uses beyond the provision of direct paths or circulation routes.