This extensive and complex field system is a Scheduled Ancient Monument. It extends some 1.2km north-east to south-west by 0.5km, across a shallow valley between Carn Llidi and the sea-coast. It is thought to have originated with a co-axial system, laid out obliquely from a bank cutting off St Davids Head (SM72752805 -SM72922838), associated with the promontory fort on the point (Nprn94974). More irregular and smaller scale enclosures and fields are assigned to the later prehistoric period and may indicate the disuse of the original system, although cultivation ridges, given a medieval dating on analogy with other sites in Dyfed, seem to follow the co-axial alignment.

Further fragments of land-division systems, superficially similar to the co-axial elements, occur elsewhere in the locality: to south of Carn llidi, above Porth-Mawr (Nprn402304), these following a different alignment; upon Carnedd-lleithr to the east (see Nprn402303) and some 3.0km to the north-east, below Carn Penberry (Nprn402302).

In 1997 Ken Murphy, an archaeologist from Cambria Archaeology, carried out a survey of the entire headland, spurred on in part by a widespread bracken fire of 1996 which had revealed many previously hidden features. At the same time RCAHMW flew several winter sorties to photograph these extensive field systems from the air, often recording faint wall lines and traces of ridge and furrow which were difficult for the ground archaeologists to see. This aerial information was mapped onto the results of the ground survey, giving a new plan of unparalleled clarity.

Sources include:
Grimes 1962 (Arch. J. 119), 336-8;
Murphy 2001 (PPS67), 85-99.
Driver, T. 2007. Pembrokeshire, Historic Landscapes from the Air, RCAHMW. Pages 95-98.

J.Wiles 18.01.05