Multiple ditch systems are enclosure complexes associated with extensive linear dykes on the chalk ridges of Wessex, dating to the later Iron Age. Sites in this class cover large areas, ranging from 25ha to 65ha, the boundaries of which are marked by discontinuous single or multiple ditches. In a number of cases, these larger dykes may enclose or demarcate as much as 700ha (as at Gussage Cow Down). Few sites in this class have witnessed systematic excavation, although fieldwork has resulted in the recovery of imported ceramics, metalwork and burials which support their attribution to the later Iron Age.
Sites in this class can be recognised and authenticated archaeologically by their morphology and associations. They are characterised by clusters of enclosure forms, a number of which (eg. banjo enclosures, viereckschanzen, and gussage style settlements) are the subjects of single monument class descriptions. A further defining characteristic is the association of these enclosure complexes with more massive single or multiple linear ditches.
Sites in this class display a number of similarities with both territorial and enclosed oppida (see separate class descriptions) insofar as they cover large areas, contain a variety of foci, and seem to have been centres within which a range of economic, political and religious services were concentrated. However, they can be distinguished from these classes of site on the basis of their morphology and distribution. They do not display the rectilinearity of territorial oppida, and contain a far wider range of enclosure classes than are found at enclosed oppida. Lack of excavation on sites in this class makes it difficult to determine whether they contain a lower frequency of imported ceramics than that which applies on territorial and enclosed oppida. Multiple ditch systems are also located to the west of the zone within which the other two classes are found.