Tomen Castell, Old Dolwyddelan

Description

Traces of a stone keep, known as Tomen Castell, crown a rocky outcrop on the edge of the floodplain of the Lledi River and overlooking the mountain road from Conwy to Ardudwy. Excavations in 1962-3 indicated that the keep was roughly 8.8m by 9.5m, with 2.3-2.95m thick walls. Additional defence was provided by a ditch cut at the western foot of the outcrop. Tomen Castell is thought to one of a small cluster of early stone-built castles constructed in Gwynedd at the end of the twelfth century, together with Castell Aber Ia (Castell Deudraeth) (NPRN 302700), Carn Fadrun (NPRN 95275), Dinas Emrys (NPRN 95284) and Castell Pen-y-garn (NPRN 407747). These were not placed to withstand alien invasion, but were rather an expression of a Prince's power and lordship in the unsettled period following the death of Owain Gwynedd in 1170 and the subsequent division of the county between his sons. The castle pre-dates the nearby Dolwyddelan Castle constructed in the early 13th century (NPRN 95299) and it is probably here rather than Dolwyddelan that Iorwerth ap Owain Gwynedd's son Llywelyn Fawr was born in c.1173 (Coflein–Louise Barker, RCAHMW, 5th June 2008)

On top of the natural knoll, the rubble built foundations of a rectangular tower were in part exposed. The building measured c.25' on its S side. The rubble walling was 7' thick on the S, where it was preserved to an external height of three to four courses laid directly on the natural surface of the knoll, but was 8 1/2 thick on the E where it was laid on an artificial raft of loosely piled stones capped with a turf layer. Within the wall was a thick bed of silt, not yet explored but showing a burnt layer towards the W end, and overlaid with a layer of tumbled stones. The ditch at the W foot of the knoll was sectioned. It was a flat-bottomed ditch, 18' wide x 3' deep cut in the shaly rock and refilled with earth and stones, the latter lying thickest at the inner end, and showing a grey layer a foot above the original bottom indicative of partial silting or filling. (Gwynedd Archaeological Trust HER ref. Jones)

The monument comprises a prominent natural rock outcrop, naturally defended on the N, S and E by a very steep rocky precipice. On the W the slope is slightly more gradual, but still very steep. The natural defences are complemented on the W and NW by a ditch, now very silted but clearly recognisable, especially on the W. The top of the mound is somewhat uneven and on the summit are traces of a rectangular structure, perhaps 6m x 6.7m. The foundations are most clearly seen on the E side. (Scheduling Report)