Ancient Monuments

History on the Ground

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Castell Llanddeiniolen

A Scheduled Monument in Llanddeiniolen, Gwynedd

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Latitude: 53.1677 / 53°10'3"N

Longitude: -4.1414 / 4°8'29"W

OS Eastings: 256949

OS Northings: 365534

OS Grid: SH569655

Mapcode National: GBR 5P.4GGL

Mapcode Global: WH54F.CM4Z

Entry Name: Castell Llanddeiniolen

Scheduled Date: 25 September 1987

Source: Cadw

Source ID: 3489

Cadw Legacy ID: CN197

Schedule Class: Defence

Category: Motte

Period: Medieval

County: Gwynedd

Community: Llanddeiniolen

Traditional County: Caernarfonshire


The monument comprises the remains of a defensive site, which resembles a medieval ringwork, although it may be prehistoric in origin. It is situated on a hill of glacial drift c.7.5m to 9m above the road which skirts its N side, the top is oval c.27.5m by 33.5m.

The N and NW slopes are steep, the E and S are more gentle, and have been scarped to form a ditch and outer bank. There is some stone at the S edge of the relatively level top of the hill, and a distinct, if slight, terrace a little further down the S side, again with some stone in the edge. The track which runs past the E side of the site is sunken, and a retaining wall over 1 m high forms the W side. This may be the line of a ditch protecting the site on the accessible E side. The base of a more recent field wall runs round the S and W sides of the site. On the NE, a gravel pit has encroached nearly to the summit of the mound.

The monument is of national importance for its potential to enhance our knowledge of prehistoric or medieval settlement and defence. It retains significant archaeological potential, with a strong probability of the presence of associated archaeological features and deposits.

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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