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Cof Cymru: National Historic Assets of Wales · Wales

Trecastell Fish Weir

Llangoed, Isle of Anglesey, Wales

The record

Designation
Scheduled monument
Site type
Fish Weir
Period
Post Medieval
Date of designation
19 November 2002
Community
Llangoed
Unitary authority
Isle of Anglesey
Country
Wales
Coordinates (centre of the scheduled area)
53.28613, -4.07004
SAM number
AN141
Cadw record number
1032

Slide toward Today to fade the historical sheet and see the modern map underneath.

David Rumsey Map Collection, Stanford Libraries

Shown on 5 historical map sheets, the earliest the 1608 "(13) Cambriae Typus." (David Rumsey Map Collection, Stanford Libraries).

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This record in Cadw's own full report ↗

Cadw's description

The following provides a general description of the Scheduled Monument.

The monument consists of the well-preserved remains of a fish weir, dating to the post-medieval period. A fish weir is usually characterised by a foundation of stone topped with a fence or row of stakes, often with nets attached forming an enclosure within a river or harbour and used for catching, or holding, fish. Trecastell Fish Weir is rectilinear, defined by spread banks of stone. The inner wall runs at 90 degrees to the shore and is some 310m long. It varies in structure from a 20m wide bank to a double line of facing-stones from 1.1 to 1.6m wide. The outer wall turns at a right angle and runs parallel to the shore for some 250m.

The monument is of national importance for its potential to enhance our knowledge of post-medieval maritime agricultural practices. It is associated with the unusual weir at Gorad Friars Bach (SH 6150 7770) and the pair of weirs at Aberlleiniog (SH 6250 7920) and therefore has significant group value. It retains significant archaeological potential, with a strong probability of the presence of associated archaeological features and deposits. The structure itself 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.

Nearby in the register

Other entries of the same register within about three miles of this one, by straight line.

Designated Historic Asset GIS Data, The Welsh Historic Environment Service (Cadw), 2026-09-07, licensed under the Open Government Licence http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/ Cadw, the Welsh Historic Environment Service · Open Government Licence v3.0
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