Llanfihangel Croesfeini chapel, demolished in 1847, stood in a field known as 'Lan capel' in 1844. The chapel's enclosure was reportedly 'D' shaped, with the chapel at its northern end, extending to approximately halfway between the chapel building and Garn Fawr Bronze Age round barrow (NPRN 303724). A 'D' shaped enclosure, dilineated by footpaths and a triangular field boundary, is visible on historic (1889) Ordnance Survey mapping. The site is located some 50m to the north of Garn Fawr. Garn fawr is situated to the immediate west of a spring which may have been utilised by both sites. A stone from the chapel (removed and used as a threshhold for an outbuilding at Waunllannau Ucha farm) was known as Carreg y Diafol ('the Devil's Stone'), and may have originally been associated with Garn fawr ('big cairn').

Sources include:
Ordnance Survey, 1889, first edition 25in

N Vousden, RCAHMW, 16 October 2012