Aside from these main activity areas, the 1,000 ha area enclosed by the defensive earthworks and rivers mainly consisted of a network of droveways, hollow ways, pastures and fields associated with cattle herding. Scattered Roundhouses and burials have been discovered amongst these droveways. The defences were designed to protect the high status and industrial areas as well as prevent cattle rustling of valuable herds. Camulodunon was surrounded by farmsteads like those at Abbotstone near Colchester Zoo and at Birch Quarry, many of which continued to exist on into the Roman period until at least the 2nd and 3rd centuries AD.