id: sig-20260722-report-cn040
site_id: gb-dolwyddelan-dolwyddelan
attribute: designation_report
value: 'Reference Number

  CN040

  Name

  Castell Dolwyddelan

  Date of Designation

  Status

  Designated

  Unitary Authority

  Conwy

  Community

  Dolwyddelan

  Easting

  272178

  Northing

  352353

  Broad Class

  Defence

  Site Type

  Castle

  Period

  Medieval

  The following provides a general description of the Scheduled Monument.

  The native Welsh castle of Dolwyddelan stands on a small rocky knoll on the southern slopes
  of Moel Siabod.  It overlooks the Lledr Valley and guards the old road from Nant Conwy to
  Meirionydd which ascends from the valley at this point. The castle consists of two towers
  connected by a curtain wall enclosing a courtyard. The buildings are all of local grit and
  slate rubble. The well-preserved appearance of the earlier SE tower or keep is due to re-occupation
  at the end of the 15th century and extensive restorations in the mid-19th century.

  There is a tradition that the castle is the birthplace of Llywelyn Fawr. His father Iorwerth
  Trwyndwn was granted the commote of Nant Conwy upon the death of Owain Gwynedd in 1170:
  it is possible therefore that the earliest work of the keep does date from the late 12th
  century. The castle was completed during the next century and during the English war was
  the royal residence of Llywelyn ap Gruffydd. It fell to the English in January 1283, and
  was immediately rearmed. There is a record of the appointment of a constable in 1284, who
  was still in office in 1290, but its isolated site far from the sea resulted in its being
  soon abandoned. The castle was re-occupied for a short time at the end of the 15th century
  by Maredudd ab Ieuan, who acquired the lease in 1488 and added a second floor to the keep.
  In the middle of the 19th century the keep was restored by Lord Willoughby de Eresby. In
  1930 the building was placed under the guardianship of the Ministry of Works.

  Architectural description - The keep is entered on its first floor by a flight of stone
  steps leading up from the courtyard to a door in the NW wall which was covered by a fore-building,
  now very ruined. This contained a small pit crossed by a drawbridge which could be raised
  against the door. The doorway has a deep chamfer continuous round the segmentally arched
  head. The 12th-century building was of one main floor, with a basement (now inaccessible)
  reached by a trap-door. The NW and SE walls of this period mostly survive, and the line
  of the original steeply-pitched gable can still be traced on the SW inner face, but much
  of the outside of this wall was completely rebuilt in the 19th century, apparently on the
  old plan.

  The NE gable wall probably incorporates a little 12th-century masonry at the base but most
  of it must be the work of Lord Willoughby. It is possible however that the doorway to the
  mural stair, and the lower steps, are actually the work of Maredudd, although no trace remains
  of a door giving access to the second floor added by him.

  The entrance floor, a single apartment, is lighted by three windows, two in the SE wall
  and one SW of the door. Each has window seats set in wide embrasures with deep roughly pointed
  rear-arches formed of thin slabs. The fireplace in the centre of the SE wall is mostly modern,
  but its back is old.

  The late 15th-century second floor, which was not replaced during the 19th-century restorations,
  was lighted by three windows. That in the SW wall has a slab lintel, and breaks the line
  of the 12th-century gable. Those in the NW and SE walls have arched heads, perhaps 19th-century
  replacements of lintels.

  The outworks consist of rock-cut ditches on the W and E; these were not needed on the S
  side, where the ground falls precipitously. To the NW, there is a wide marshy area partly
  caused by the damming of a small stream by the causeway carrying the old road. The original
  entrance crossed the E ditch on the line of the present approach.

  The 13th-century curtain wall, 4ft 6 ins to 5ft 6ins thick, is very ruined, but still stands
  to a height of about 8ft near the junction with the S wall of the keep. The main gateway
  was on the NE near the NW tower; but there was another opening through the same wall near
  the keep. One jamb of a loop exists in the best preserved section of the S curtain. Access
  to the wall-walk must originally have been by wooden steps of which no trace survives. Later,
  an approach was provided from the first floor of the NW tower by a newel stair in its S
  wall. At a later date, perhaps c.1490, a straight flight of stone steps was built against
  the outside of this wall, blocking the ground floor loop. NE of the keep, a thin wall, probably
  13th-century, continues the line of the N curtain to the brink of a steep drop. A small
  postern with deeply splayed reveals leads from the enclosure, which was otherwise inaccessible
  except by ladders.

  The NW tower was built within the angle of the earlier curtain; straight joints ware visible
  at both junctions. It is very ruined, but the E wall stands to a height of about 26ft. The
  tower probably had two floors, each a single room. It was entered from the courtyard by
  a wide door, with jambs of sandstone which appears to be the only imported stone on the
  site. The ground floor seems to have been lighted by narrow slits to the courtyard. A doorway
  in the N wall leads to a latrine and a flanking chute indicates another on the wall-walk
  above; these precede the building of the tower. In the E wall, above a line of beam-holes
  indicating the first-floor level, there is a large fireplace with canopied hood. From the
  embrasure of a window to the S there are remains of a stair which probably led to the roof
  and curtain wall-walk. The base of a small rectangular bastion added to the W wall contains
  two latrine outlets, which probably served the first-floor apartment of the tower.

  There are scheduled remains [CN196] of another medieval defensive site, possibly a precursor
  to Dolwyddelan, on a rocky knoll 350m to the SE. The remains consist of a defensive ditch
  around the west side of the knoll, and the foundations of a tower on top.

  The monument is of national importance for its potential to enhance our knowledge of medieval
  defence. It retains significant archaeological potential, with a strong probability of the
  presence of associated archaeological features and deposits. The structures themselves may
  be expected to contain archaeological information concerning chronology and building techniques.

  The scheduled area comprises the remains described and areas around them within which related
  evidence may be expected to survive.'
source_url: http://cadwpublic-api.azurewebsites.net/reports/sam/FullReport?lang=en&id=3406
source_title: Scheduled Monument Full Report — Castell Dolwyddelan
publisher: Cadw
observed_date: '2026-07-22'
collected_by: scripts/build_assessment_batch.py
confidence: high
notes: The designation text. Assess the six bands against THIS evidence only; omit any band
  it does not speak to.
