Ancient Monuments

History on the Ground

This site is entirely user-supported. See how you can help.

Colwyn Castle

A Scheduled Monument in Glascwm (Glasgwm), Powys

We don't have any photos of this monument yet. Why don't you be the first to send us one?

Upload Photo »

Approximate Location Map
Large Map »

If Google Street View is available, the image is from the best available vantage point looking, if possible, towards the location of the monument. Where it is not available, the satellite view is shown instead.


Latitude: 52.1768 / 52°10'36"N

Longitude: -3.3074 / 3°18'26"W

OS Eastings: 310694

OS Northings: 253972

OS Grid: SO106539

Mapcode National: GBR YS.546L

Mapcode Global: VH69V.MKC4

Entry Name: Colwyn Castle

Scheduled Date:

Source: Cadw

Source ID: 1919

Cadw Legacy ID: RD035

Schedule Class: Defence

Category: Motte & Bailey

Period: Medieval

County: Powys

Community: Glascwm (Glasgwm)

Traditional County: Radnorshire


The monument comprises the remains of a motte and bailey castle, built over the remains of a Roman fort. A motte and bailey is a military stronghold built during the medieval period and comprises a large conical or pyramidal mound of soil or stone (the motte) surrounded by, or adjacent to, one or more embanked enclosures (the bailey). Both may be surrounded by wet or dry ditches and could be further strengthened with palisades, revetments, and/or a tower on top of the motte. At Colwyn Castle, the top of the motte, which is c.65m in diameter, is still occupied by a modern farm. This area is surrounded on all sides except the south-west by a ditch, the base of which is up to c.6m below the level of the summit, with a counterscarp bank beyond standing up to c.4m high above the base of the ditch and c.1m above the surrounding ground surface. The motte stands at the junction of two contiguous sub-rectangular bailey enclosures forming an area c.280m by c.160m in total, surrounded by a bank and ditch. The bailey bank stands up to c.0.5m above the interior on the south-west, but is reduced to a scarp elsewhere; both bank and scarp stand c.1m high externally. The ditch is still visible at the south-west and north-east ends of the bailey and at points along the north-west side, but is largely lost on the south-east side. The south-western portion of the bailey overlies a Roman fort, thought to measure c.160m square; traces of a presumed north corner can be seen to the north-west of the motte. Finds of pottery from badger earths suggest that this fort belongs to the earliest campaigns in Wales in the AD 50s. There are traces outside the north-western and south-western sides of a further slight defence about 16m beyond the main line, forming an annexe. Geophysical survey has failed to locate any associated civilian settlement, or indeed much detail of either Roman or medieval features. Colwyn Castle is mentioned in documentary sources in 1144 and is thought to have been reconstructed in stone c.1240. It was demolished in 1629.

The monument is of national importance for its potential to enhance our knowledge of medieval and Roman defensive organisation. The well-preserved monument forms an important element within the wider medieval and Roman context and the structure itself may be expected to contain archaeological information relating to chronology, building techniques and functional detail.

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

Source: Cadw

Other nearby scheduled monuments is an independent online resource and is not associated with any government department. All government data published here is used under licence. Please do not contact for any queries related to any individual ancient or schedued monument, planning permission related to scheduled monuments or the scheduling process itself. is a Good Stuff website.