Ancient Monuments

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Y Gaer

A Scheduled Monument in St. Nicholas and Bonvilston (Sain Nicolas a Thresimwn), Vale of Glamorgan (Bro Morgannwg)

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Latitude: 51.4638 / 51°27'49"N

Longitude: -3.3497 / 3°20'58"W

OS Eastings: 306337

OS Northings: 174738

OS Grid: ST063747

Mapcode National: GBR HQ.M04G

Mapcode Global: VH6F9.WGJN

Entry Name: Y Gaer

Scheduled Date:

Source: Cadw

Source ID: 408

Cadw Legacy ID: GM079

Schedule Class: Defence

Category: Ringwork

Period: Prehistoric

County: Vale of Glamorgan (Bro Morgannwg)

Community: St. Nicholas and Bonvilston (Sain Nicolas a Thresimwn)

Traditional County: Glamorgan


The monument comprises the remains of an Iron Age (800BC-AD74) defended enclosure. It consists of two oval concentric enclosures, separated by a space of approximately 10m. The inner enclosure measures 65m long from east to west by 50m, the outer measures 120m long by about 105m.

Each enclosure is defended by a single bank which has been reduced to a scarp except on the eastern and western sides of the inner circuit and on the north-west of the outer circuit. The banks are 10.5 to 12m wide. The internal height of the banks is slight except on the north-west of the outer circuit where it reaches 1.5m. The external bank height averages nearly 2.5m. A shallow external ditch 6-9m wide is visible along part of the western side. The entrance through both ramparts is on the north; the inner entrance appears to be slightly in-turned but its western side is disturbed. A stony hollow at the centre of the enclosures is probably the site of a building which is shown on the Ordnance Survey map of 1813.

The monument is of national importance for its potential to enhance our knowledge of late prehistoric defensive organisation. The monument forms an important element within the wider Iron Age context and may be expected to contain archaeological information in regard to elements such as chronology, building techniques and social organisation.

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

Source: Cadw

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