Earthwork and cropmark remains of a Late Iron Age/early Roman enclosure complex. Situated at the southern end of an island of raised ground in the fens, the outermost earthworks enclose an area of 9.1 hectares, but aerial photography and excavation suggest that the earthworks had also been complemented by a network of now extinct water channels. The site has seen much surface collection over the last 40 years, along with three episodes of excavation - single trenches across ramparts in 1959 and 1980 (the latter as part of a programe of excavation that came to focus on the Roman activity to the north - see TL49SW 29 and other associated monuments), and some more extensive work in the early 1990s associated with work to reinstate the earthworks (which had largely been ploughed out since the 1950s). It is clear that the extant earthworks represent more than one phase of construction - three have been tentatively suggested, although excavations to date have been of limited use in establishing the correct sequence. No stratified, datable finds have come from any of the bank and ditch sections of the main earthworks, for example. Most artefacts have been recovered during fieldwalking and metal detecting, although some human remains turned up in the early 1990s trenches, including a childs skull bearing cut marks from a knife or sword and radiocarbon dated to 2070+/-65 BP (uncalibrated), and a complete adult male skeleton in upper ditch fill radiocarbon dated to 1985+/-55 BP (uncalibrated). It is clear, however, that the camp overlies at least one and possibly 3 ring ditches of Early Bronze Age date, as well as indications of Neolithic activity (see associated records). Jackson & Potter suggest an origin for the site in the late Iron Age, possibly as an infrequently visited centre of a ritual nature (on the basis of the scarcity of finds and features indicative of any more intensive occupation), with the main period of activity falling in the period circa 40-60 AD.