The entire extent of each historic town is protected within the boundaries of their respective national park, which are also, collectively, the boundaries of the World Heritage property, and no development other than that which serves site protection, conservation and interpretation is allowed. There is no through traffic within the parks, and all activities within the parks are strictly controlled, including the protection of the historic landscape and the strict regulation of the use of the monuments (most of which are the remains of former temples or Buddhist monasteries). This ensures that the archaeological, as well as the historic integrity of the monuments, and the relationship of one to another is maintained.