The scant remains of Castell Aber Ia stand at the south western tip of a short rocky ridge in woodland known as Y Gwyllt to the west of Portmeirion village. All that remains of this small castle is the relatively level rock platform some 20m east-west by 26m north-south, upon which a stone tower once stood. The south, east and western sides of the platform are defined by steep crags some 6-7m high, whilst to the north, the platform has been cut off from the gently sloping ridge by a rock cut ditch and counterscarp bank. Across this side of the platform, small sections of dry stone walling suggests there was once a curtain wall here, and it seems likely this would also have been where the gate was located, accessed by a bridge across the ditch. Two other small sections of surviving wall suggest that other defensively weak points around the circuit may also have been strengthened.

The castle was demolished in the mid-nineteenth century by a tenant of the Aber Ia estate. Prior to this it served as a scenic viewpoint with the tower described in the nineteenth century as being semi-circular in shape and some 4m in diameter. The Campanile in Portmeirion village bears a plaque noting its construction from the stone of the castle; whilst the original site is now known as `Castle Rock? and used as a viewing point. Here sections of battlemented wall were constructed at the tip of the ridge by Clough Williams-Ellis in the 1960s, and a circular gazebo placed on the eastern edge of the platform in 1983.

This castle has often been associated with the `Castle of Deudraeth' mentioned by Gerald of Wales as newly built in 1188; there is however some debate over this association. It does however seem likely that Aber Ia was one of a small cluster of early stone-built castles constructed in Gwynedd at the end of the twelfth century, together with Carn Fadryn (NPRN 95275), Dinas Emrys (NPRN 95284), Tomen Castell (303046) and Castell Pen-y-garn (NPRN 407747). These were not placed to withstand alien invasion, but rather as 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 Kingdom between his sons.

Louise Barker, RCAHMW, 5th June 2008-06-05

Sources
Beverly Smith J and Llinos 2001 History of Merioneth Vol II: The Middle Ages, 409-410
Hemp WJ 1949 `Castell Aber Ia? Archaeooigia Cambrensis vol 100, 311-312
Morris TE 1927 `The Castle of Deudraeth' Archaeologia Cambrensis vol LXXXII, 355-364
RCAHMW 1921 Inventory for the County of Merioneth, 161 No. 515