The Coflein 2010 entry for this site (sadly) lists this as a YSBYTTY CYNFYN, DISCREDITED STONE CIRCLE;YSBYTY CYNFYN STONE CIRCLE, with a very short description: "Suggested embanked stone circle around the churchyard thought to be the remains of the churchyard wall demolished in 1901."
They add the source for the full documentation and investigation can be found at "Briggs, C.S. 1979, 'Ysbyty Cynfyn churchyard wall', Arch. Camb. 128, 138-46. Also, Cardiganshire County History Volume 1, 1994, pages 139-142." A second entry for the church, recorded in 2014, ST JOHN'S CHURCH;ST JOHN THE BAPTIST, YSPYTTY-CYNFYN;YSBYTY CYNFYN, says: "St John's Church is situated within a curvilinear churchyard some 40m north of the Nant Ysbytty Cynfun. The churchyard has three large standing stones set into the southeast curve of its boundary, which may represent the remains of a prehistoric stone circle. It has also been suggested that the stones, first recorded in 1833, were placed here as a nineteenth-century folly."
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