Ancient Monuments

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Caer Siac Motte and Bailey

A Scheduled Monument in Bettws (Betws), Powys

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Latitude: 52.5658 / 52°33'56"N

Longitude: -3.286 / 3°17'9"W

OS Eastings: 312926

OS Northings: 297216

OS Grid: SO129972

Mapcode National: GBR 9T.CHN2

Mapcode Global: WH7B0.HRFW

Entry Name: Caer Siac Motte and Bailey

Scheduled Date: 10 May 2019

Source: Cadw

Source ID: 4402

Cadw Legacy ID: MG342

County: Powys

Community: Bettws (Betws)

Traditional County: Montgomeryshire


The monument comprises the earthwork remains of a medieval motte and bailey castle, a form of earth and timber castle comprising an artificial ditched mound with adjacent enclosed court or bailey. It occupies a strong position straddling a narrow and steep-sided, south-west to north-east aligned ridge with good views in all directions. The motte occupies the full width of the highest and narrowest part of the ridge and is defined by defensive ditches cutting the approaches to the north-east and south-west. The remaining flanks of the mound merge with steep natural slopes. It is a small example of its class, measuring up to 3.5m in height. The uneven summit measures 10m in diameter. The RCAHMW described a more substantial earthwork in 1911, and it is possible that its present dimensions are the result of vehicular damage during the mid-twentieth century. The motte ditches measure 0.3m to 1m in depth, although their lower levels and fills are likely to survive as buried deposits. The exposed end of the south-western ditch is almost vertically sided. The lower levels of the motte remain undisturbed and are likely to retain archaeological evidence of its construction and a buried medieval land surface. There are traces of baileys or subsidiary enclosures to either side of the motte. The smaller enclosure occupies the narrow and level ridge summit to the south-west and measures a maximum of 15m in width, defended by steep natural slopes. A now denuded and irregular bank cut off the approach along the ridge approximately 30m from the motte. Aerial photographic evidence suggests a back-filled ditch along this line. The north-eastern bailey was larger and occupied a broader, almost level, oval shelf of ground, again defended by steep slopes to the north and south. There are no signs of upstanding earthworks beyond scarps, although aerial photographic evidence indicates possible ditches in this position.

The monument is an unusual example of its class with a small central motte and flanking baileys but with few other signs of defensive earthworks other than natural slopes. The castle is undocumented but its form, layout and location in the Powys cantref of Cedewain, less than 1km from the clas or mother church at Bettws Cedewain suggest that it is of Welsh origin. In spite of twentieth century damage the monument is likely to retain significant buried archaeological deposits containing structural, artefactual and environmental evidence. These have high potential to enhance our knowledge of the form, date, development and occupation of the castle and also increase our understanding of medieval Welsh defensive and domestic practices, constructional methods and material culture.

The scheduled area comprises the remains described above and an area around them within which related evidence might be expected to survive. It is an irregular polygon in shape on plan and measures a maximum of 155m north-east to south-west by 45m transversely.

Source: Cadw

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