A fragment of a bowl or dish of black ware with a groove on the rim was noted as found at Dinas Dinlle hillfort (NPRN 95309) in June 1954 (RCAHMW 1960, 190). 

Gardner and Savory (1964, 215) note it was found by Mr W. E. Griffiths in the edge of the cliff, and describe it as a rim from a black flanged and conical bowl of the late 3rd to the middle of the 4th century AD.

Louise Barker, CHERISH Project RCAHMW, May 2023.

CHERISH PROJECT. Produced with EU funds through the Ireland Wales Co-operation Programme 2014-2020. https://cherishproject.eu/en/

Sources:

Gardner, W. and Savory, H. N., 1964 Dinorben. A Hill Fort Occupied in Early Iron age and Roman Times (Cardiff: National Museum of Wales).

RCAHMW, 1960, An Inventory of the Ancient Monuments in Caernarvonshire. Volume II: Central (Monument Number 1211, 190).