Miscellaneous Pegwyn Mawr II Ring Cairn Kammer Aug 23, 2004 The NMR (available through Coflein) describes Pegwyn Mawr II as a possible ring cairn:An unbroken bank, 2.0-4.0m wide and 0.6-0.9m high, encloses an area 10m in diameter, and has an Os triangulation pillar upon its SW.