Ancient Monuments

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Anti-invasion Defences 630m east of Cae'r-tyddyn

A Scheduled Monument in Brithdir and Llanfachreth (Brithdir a Llanfachreth), Gwynedd

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Latitude: 52.7395 / 52°44'22"N

Longitude: -3.7855 / 3°47'7"W

OS Eastings: 279554

OS Northings: 317263

OS Grid: SH795172

Mapcode National: GBR 95.0DM4

Mapcode Global: WH67V.TDLN

Entry Name: Anti-invasion Defences 630m E of Cae'r-tyddyn

Scheduled Date: 8 June 2006

Source: Cadw

Source ID: 1173

Cadw Legacy ID: ME250

Schedule Class: Defence

Category: Anti-tank Obstacle

Period: Post Medieval/Modern

County: Gwynedd

Community: Brithdir and Llanfachreth (Brithdir a Llanfachreth)

Traditional County: Merionethshire


The monument consists of anti-invasion defences, dating to the early period of World War II (AD 1940-41), that formed part of Western Command Stop Line No. 21, which ran from Rhyl to Machynlleth. The defences are located on the Bwlch Oerddrws pass on the A470 trunk road between Dolgellau and Dinas Mawddwy, where the local topography forms a steep-sided, narrow and easily defended gorge. Twenty-five in situ anti-tank cubes are aligned N-S and defend an upward position to the E. The structure measures c. 72m long and is bisected by the A470. Fifteen cubes lie to the N of the road in a NNW-SSE alignment c. 36m long and ten lie to the S in a N-S alignment 25m long. They are built of concrete and faced with local stone. The anti-tank cubes are regular in shape and measure c. 1.6m wide, 1.6m tall and 1.6m deep.

The monument is of national importance for its potential to enhance our knowledge of World War II anti-invasion practices. The monument is well preserved and is an important relic of actions taken against the perceived threat of a German invasion from Ireland. It retains significant archaeological potential, with a strong probability of the presence of associated archaeological features and deposits.

The area scheduled comprises the remains described and areas around them within which related evidence may be expected to survive. Area 'A' is centred on Item 'A' (NGR SH 79552 17281). It is an irregular rectangle in shape and measures 40m NW-SE by 9m transversely. Area 'B' is centred on Item 'B' (NGR SH 79556 17240). It is an irregular rectangle in shape and measures 28m N-S by 9m transversely.

Source: Cadw

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