1. A circular enclosure with an apparent segmented ditch was first noted during RCAHMW summer aerial reconnaissance in 1996 as a cropmark in fields 80m south-east of St Andrew's Church, Bayvil (NPRN 225), partially underlying a modern hedgebank. At the time the enclosure appeared to represent a prehistoric ritual monument, such as a barrow or a henge monument.

Reference:
Driver, T. 2007. Pembrokeshire Historic Landscapes from the Air. RCAHMW. Page 120, Fig. 181.

2. Magnetometry and excavation by Mike Parker-Pearson and Kate Welham in September 2014 showed that the Bayvil enclosure measures c. 70m diameter with a possible segmented ditch. Excavations yielded prehistoric pottery. The team noted that a number of potential standing stones had been removed from the field in the 1970s, which may have been associated with the enclosure.

T. Driver, RCAHMW, 2014.