SUSSEX ARCHAEOLOGICAL COLLECTIONS 138 (2000), 15–28 Important archaeological discoveries made during the construction of the A259 Rustington Bypass, 1990 INTRODUCTION by David Rudling & Oliver Gilkes A watching brief and rescue excavations during the construction of the A259 Rustington Bypass revealed finds and features of the prehistoric and Roman periods. A concentration of Roman remains at the northern end of Penfold Lane was of particular importance. These included a number of Roman quernstones and millstones, nearby undated waterlogged timbers and, given the proximity of a watercourse (the ‘Black Ditch’), these may indicate a connection with watermilling. This article reports upon the most significant findings. ◆ a few oyster shells) may be due to soil conditions. The fieldwork at Site 6 also included excavation and recording of various features, including three ditches, a possible granary, and a timber building with a chalk-and-clay floor. The ditches were probably necessary to drain water, given the low- lying location of Site 6 (under 5 m OD) and the environmental evidence from the ditch in Area I (see microfiche). Time and resource constraints limited the investigation of Site 6; the area containing the undated waterlogged timbers and stakes may have been particularly interesting. Further traces of Roman activity (i.e. finds and features) were uncovered at Sites 3 and 7. The absence of features and significant quantities of finds dating to the medieval and post-medieval periods may indicate that settlement in the area declined after the Roman period, although four coins spanning the period c. 1154–1483 were recovered. Both earlier and subsequent fieldwork in the vicinity of the bypass has revealed a similar intensity of archaeological evidence (Gilkes 1993; Gilkes & Hammond 1991; Lovell 1998; Rudling 1990; Weaver 1995; and entries in the West Sussex County Council Sites and Monuments Record). Clearly, the Roman occupation took the form of an extensive area of settlement features and field systems, together with some industry, such as the postulated watermill at Site 6 and pottery production at the former Horticulture Research International (HRI) site near the western end of the bypass (Fig. 1; Lovell 1998). D iscoveries during a watching brief and rescue excavations during the construction of the A259 Rustington Bypass show that this area of the West Sussex Coastal Plain is rich in archaeological remains. The oldest finds are flintwork, and include (from Site 4) a fragment from a possible Mesolithic bladelet, a Neolithic polished flint axe fragment, and flakes, including two probable axe-thinning examples, which may be Neolithic. Site 4 also yielded two endscrapers and flint debitage which has a broad Neolithic/Bronze Age date range. Similar small assemblages of flintwork of Neolithic/Bronze Age date were found at other sites, e.g. Site 6. An urned cremation at Site 1 is thought to be of Bronze Age date. Of uncertain prehistoric date was a thick spread of burnt flint at Site 2 and this may indicate a burnt mound (cf. Stevens 1997). Several locations yielded evidence for later prehistoric activity, including a gold pennanular ring from Site 6, and pottery finds from Sites 3, 6, 7 and 8. Romano-British evidence centring on the 1st and 2nd centuries AD concentrated at Site 6. The large amounts of pottery and metalwork probably indicate settlement activity, whilst the many fragments of quernstones and millstones imply that milling was one function of the site, perhaps watermilling, given the site’s proximity to the ‘Black Ditch’ watercourse. The relatively small quantities of food remains (i.e. the animal and fish bones, and