Ancient Monuments

History on the Ground

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Cefn Morfydd Dyke & Earthwork

A Scheduled Monument in Tonna, Neath Port Talbot (Castell-nedd Port Talbot)

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Latitude: 51.6684 / 51°40'6"N

Longitude: -3.7548 / 3°45'17"W

OS Eastings: 278740

OS Northings: 198082

OS Grid: SS787980

Mapcode National: GBR H5.6087

Mapcode Global: VH5GN.VBVC

Entry Name: Cefn Morfydd Dyke & Earthwork

Scheduled Date:

Source: Cadw

Source ID: 396

Cadw Legacy ID: GM264

Schedule Class: Monument

Category: Linear earthwork

Period: Early Medieval

County: Neath Port Talbot (Castell-nedd Port Talbot)

Community: Tonna

Traditional County: Glamorgan


The monument consists of the remains of a dyke, a defensive boundary or earthwork, dating to the later prehistoric/medieval period.

The dyke and earthwork are situated on the north-east slop of Cefn Morfudd facing low ground to the north-west. The ends of the dyke are c. 410m apart, the middle of the dyke curving in towards the south-west. The western section comprises of a bank and ditch. The dyke is broken through at various points by tracks and watercourses. The earthwork lies approximately 90m south-west of the western end of the dyke. It is oval in shape, measuring c. 60m by c. 40m. The bank and ditch are best preserved on the eastern side and there is an entrance on the north-east.

The monument is of national importance for its potential to enhance our knowledge of later prehistoric/medieval defensive organisation and settlement. It retains significant archaeological potential, with a strong probability of the presence of associated archaeological features and deposits. A dyke may be part of a larger cluster of monuments and their importance can further enhanced by their group value.

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

Source: Cadw

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