Ancient Monuments

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Cwm Nash Defended Enclosure

A Scheduled Monument in St. Donats (Sain Dunwyd), Vale of Glamorgan (Bro Morgannwg)

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Latitude: 51.4219 / 51°25'18"N

Longitude: -3.5711 / 3°34'15"W

OS Eastings: 290858

OS Northings: 170377

OS Grid: SS908703

Mapcode National: GBR HD.PQGQ

Mapcode Global: VH5HY.1JZC

Entry Name: Cwm Nash Defended Enclosure

Scheduled Date: 18 December 2008

Source: Cadw

Source ID: 1290

Cadw Legacy ID: GM614

Schedule Class: Defence

Category: Promontory Fort - inland

Period: Prehistoric

County: Vale of Glamorgan (Bro Morgannwg)

Community: St. Donats (Sain Dunwyd)

Traditional County: Glamorgan


The monument comprises the remains of a multivallate defended enclosure, which probably dates to the Iron Age period (c. 800 BC - AD 43). The enclosure is located on a south-west-facing inland promontory situated within the coastal fringe. It is sub-circular in shape on plan. The steep wooded slopes of Cwm Nash mark the defensive circuit on the south and west sides. Two close-set and curvilinear banks of earth and stone with external ditches and a third outlying bank protect the north and east sides. The inner and outer close-set banks measure 4.25m and 4.6m in width respectively. Both ditches measure 3m in width. Each bank stands 1.75m above the bottom of the ditch. The inner enclosure measures 38m north-west by south-east by 18m transversely. It is accessed via a causeway across the ditches and simple gaps through the banks on the north-east side. The causeway is aligned north-east by south-west and measures 3m in width. The third outlying bank is located on the north-west, north and north-east sides of the inner enclosure. It measures 0.8m in height and 3m in width. The bank protects the entrance to the inner enclosure and defines an annexe.

The monument is of national importance for its potential to enhance our knowledge of later prehistoric defensive organisation and settlement. The site forms an important element within the wider later prehistoric landscape. It is well preserved and retains considerable archaeological potential. There is a strong probability of the presence of evidence relating to chronology, layout, building techniques and functional detail.

The scheduled area comprises the remains described and an area around them within which related evidence may be expected to survive.

Source: Cadw

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