id: sig-20260722-report-br126
site_id: gb-maescar-du-sennybridge
attribute: designation_report
value: 'Reference Number

  BR126

  Name

  Castell-Du, Sennybridge

  Date of Designation

  Status

  Designated

  Unitary Authority

  Powys

  Community

  Maescar

  Easting

  291971

  Northing

  228400

  Broad Class

  Defence

  Site Type

  Castle

  Period

  Medieval

  Castell Du, also known as Rhyd y Briw, consists of the remains of a castle, dating to the
  medieval period. The castle is located on the SW side of Sennybridge and commands the crossing
  of the river Senny at its junction with the Usk. The remains consist of a stone wall 26m
  in length, orientated ENE/WSW, with a D-shaped tower projecting from the centre. The tower
  is 6m in diameter and stands to a maximum height of 6m. Much of the original facing stone
  has been lost, exposing the rubble interior, although a section survives on the W side.
  Below the tower on the E side is a large chunk of fallen masonry lying on its side, surrounded
  by fallen stones. To the W of the tower is a stretch of turf-covered walling, probably the
  remains of a range. Most of this walling is hidden below the vegetation, but one section
  stands to 2m high adjacent to which is a narrow stone-built passage that leads into the
  extant WWII pillbox. This pillbox is one of two built on the castle site using masonry to
  mimic the castle walling. The second, on the E side, now lies within a neighbouring garden.
  Little is known of the history of the castle, although it is thought to have been constructed
  by Llywelyn ab Gruffudd around 1262. Records suggest that it was possibly the ''new castle
  beyond Brecon'' destroyed by the then Lord Edward (later Edward I) in 1265. The surviving
  structural elements on the site may belong to a subsequent castle, as records show the use
  of the Rhy y Briw into the 1270s.

  The monument is of national importance for its potential to enhance our knowledge of medieval
  defensive practices. The monument is well-preserved and an important relic of the medieval
  landscape. It retains significant archaeological potential, with a strong probability of
  the presence of both structural evidence and intact associated deposits.

  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=1761
source_title: Scheduled Monument Full Report — Castell-Du, Sennybridge
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.