1. Rug mound has been excavated on several occasions revealing that it is a castle mount raised over an earlier funerary monument. It has been identified with the Castle of Edeirnion mentioned in 1160. The only other castle site in the commote is Owen Glyndwr's Mount (NPRN 300518) on the other side of the Dee.
The original mansion of Rug stood immediately north of the mound (illustrated in Arch. Cam. IV (1887), facing 48 & JMHRS I (1949-51), plate 1.12) and is likely to have originated in a medieval house. This is one of several instances in Merioneth where an apparently unfortified mansion is associated with a castle mound, for example Castell Prysor (NPRN 308964) and Crogen (NPRN 306558).
This house was replaced by the present mansion at the end of the eighteenth century. The mound had by then been adapted as a landscape or garden feature (see NPRN 265144) and a sketch of about 1700 (reference above) shows it girdled by a wall or path and topped by a tall mast. In the 1690s Lhuyd observed that it was 'adorn'd for an ornamt'. Footings of an octagonal building, 7.8m across, excavated on the summit of the mound probably represent a summer or banqueting house. A standing stone set south of the mound (NPRN 306599) is likely to be a garden feature.
The mound is roughly oval, some 30-32.5m across and 3.7m high, with a level summit about 10-12m across. It was first opened in 1875 and was further explored when a storeroom was constructed within it. More scientific excavations were conducted in 1921.
The funerary monument consisted of a rough cists, containing fragments of burnt bone, within a cairn about 1.6m across. This was enclosed first by a low wall or kerb, 8.0m in diameter, and then by the oval outer kerb, 32.5-35m across. The castle mound was raised over this kerbed enclosure, and was surrounded by a V-profile ditch, 6.5m wide and 3.0m deep. Seven bone draughts counters were found in 1878-9.

Sources: Willoughby Gardner in the Journal of the Merioneth Historical & Record Society 4 (1961-4), 3-6
History of Merioneth I (1967), 76-77
History of Merioneth II (2001), 414

John Wiles 10.07.07

2. Depicted on the Second Edition Ordnance Survey 25-inch map of Merionethshire VII, sheet 16 (1901). C.H. Nicholas, RCAHMW, 21st August 2006.

3. RCAHMW aerial reconnaissance in drought conditions on 31st July 2006 recorded a number of parchmarks around the motte, including the clear line of the plough-levelled bailey to the north-east, and a variety of other cropmarks including those of a rectangular ditched structure. See RCAHMW aerial photographs AP_2006_3965 to 3970.

T. Driver, RCAHMW, 30th Jan 2009.