Running NNW to SSE, crossing the entire length and dividing Cardigan Island is an earthen bank around 250m in length, 3m wide and standing no more than 0.5m high. The bank is likely to be prehistoric in date with aerial photographs and evidence on the ground indicating that it is cut by and thus pre-dates the islands promontory enclosure (NPRN309338). The section of bank within the promontory also preserves traces of a ditch on the eastern side, a feature not visible elsewhere. There appears to have been a slight alteration in the course of the bank as it approached the promontory enclosure, with a 5m stretch turning more sharply to the north-west. The bank also shares a relationship with a possible round house NPRN 421078 at its southern end (SN 16115 51500). It is not clear whether the roundhouse predates the bank and was later incorporated into it or if the feature was constructed against the bank.

There is one 2.5m gap through the bank at SN 16044 51616, 21m south of the promontory enclosure. This may well be an original feature but could also date to a later period when the island was cultivated. Plough furrows (NPRN 309342) are evident on either side of the bank and are aligned to it. The fact that the bank survives in a relatively good condition suggests it has served a function ? most likely relating to land division and use - throughout the long history of the island.

This feature was surveyed by P. Brewers in 1992 and was revisited by the Royal Commission in 2013. The island has been documented during RCAHMW aerial reconnaissance.

Louise Barker, RCAHMW, June 2015

Sources
Brewers P., 1993 Cardigan Island: A survey. Unpublished B. A. Dissertation submitted to the Department of Archaeology, St David's University College, Lampeter.
Brewers P., 1994 Cardigan Island, Y Ferwig (SN 161 515). Archaeology in Wales 34, 3-6