During Royal Commission aerial reconnaissance on 24th July 2006, a remarkable series of cropmarks were discovered to the north-east of St Donat's in the Vale of Glamorgan which described a series of trackways, boundaries and other markings of a complexity rarely seen in the cropmark archaeology of south Wales.

The St Donat's cropmarks lie almost a kilometre north-east of St Donat's Castle and encompass an area of some 18 hectares. The principal remains of the settlement comprise an east-west ditched trackway visible for 530m which varies between 5-6m wide in its central and western part, but kinks in a dog-leg towards its eastern end and widens to some 12m. To the north and south of the trackway extend a series of rectangular and polygonal enclosures, presumably fields, of varying sizes. To the north-west of the trackway the field boundaries splay and diverge, perhaps as they move away from the nucleus of the settlement. To the south of the trackway, the order and alignment of the enclosures is preserved, and reinforced by an apparent T-junction with the main track giving access to a second parallel track further to the south. Between these two parallel tracks, an intermediate east-west boundary on the same alignment reinforces the suggestion of an ordered, if not planned, set of plots and fields. In the south-east corner of the cropmark complex are two rather more distinct enclosures, one broad-ditched and square measuring 26m across, the other more irregular and polygonal measuring up to 42m across; both are linked by an intervening ditch. Throughout the complex of fields, plots and trackways are frequent pits of varying sizes. Some are no doubt former clay pits or limestone quarries as are common in this part of the Vale, while others which preserve the general alignment of the settlement could be seen as rubbish pits or the remnants of other settlement features.

The most distinctive and recognisable cropmarks occur on the north-west peripheries of the settlement, in the form of a pair of ploughed out round barrows presumably of Bronze Age date. The larger (west) barrow is 22m diameter with a ditch up to 3m wide in places. The smaller (east) barrow is 12m diameter with a more narrow ditch; the barrows lie 23m apart. Round barrows are reasonably common throughout the Vale of Glamorgan and a pair of upstanding tumuli lie 600m due north at Ffynnon-y-capel, Somerset Farm. The barrows are respected by, and incorporated within, the main field system described; indeed the smaller barrow has been used to align a field corner and is partly slighted by this later boundary. A much later boundary, on the same axis as present field boundaries, cuts through the larger barrow and is itself ploughed-out.

Of crucial importance to the establishment of a likely date for the settlement and field system is the fact that it is overlain by cropmarks of a former ridge and furrow field system, a gently-curving parallel set of cultivation lines on average 10m apart running generally north-south. Initial examination of the aerial photography in 2006 suggested these cultivation lines were integral to the settlement and field system, springing from either side of the central trackway, and making a medieval date likely for the complex. Only more intensive, recent, analysis of the cropmarks by the author and by Sal Garfi during air photo mapping has shown that both the trackways and distinct enclosures are cut through and overlain by the ridge and furrow. This ridge and furrow has itself become an archaeological layer as it is overlain by, and on a different alignment to, the present field boundaries whilst also being at odds with the pattern of surviving strip-fields running north-east from St Donat's.

The east-west orientation of the settlement and its stratification below both ridge and furrow cultivation and the present field system suggests an early, pre-medieval date. The possibility arises of a Romano-British settlement and field system which has hitherto been unsuspected on the outskirts of the medieval settlement of St Donat's.

T. Driver, RCAHMW, 18th March 2009