Ancient Monuments

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Castell Crwn

A Scheduled Monument in Cylch-y-Garn, Isle of Anglesey (Ynys Môn)

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Latitude: 53.3879 / 53°23'16"N

Longitude: -4.5098 / 4°30'35"W

OS Eastings: 233187

OS Northings: 390831

OS Grid: SH331908

Mapcode National: GBR HM7R.8YV

Mapcode Global: WH424.P3PL

Entry Name: Castell Crwn

Scheduled Date:

Source: Cadw

Source ID: 3253

Cadw Legacy ID: AN029

Schedule Class: Defence

Category: Ringwork

Period: Medieval

County: Isle of Anglesey (Ynys Môn)

Community: Cylch-y-Garn

Traditional County: Anglesey


The monument comprises the remains of a well preserved castle-ringwork, which dates to the medieval period (c. AD 1066 - 1485). The monument comprises the remains of a circular earthwork comprising a bank, external ditch and remains of a counterscarp bank, with an internal diameter of 24-25m. It is situated in a slight depression 20m E of a small stream flowing N to the sea.

The defences are best preserved on the W side, where there is an outer bank 0.3-0.5m high, a fall to the bottom of the ditch of about 1 m and then a climb of 2m to the top of the internal bank. The internal bank lies between 0.75m and 1.5m above the level of the interior. The ditch has been filled in on the E and NE sides, but is still just visible. It is possible that the ditch was filled with water from the adjacent stream.

A modern field bank cuts through the S part of the site, causing some damage to the banks. The site is generally better preserved S of this wall, although parts of it are very overgrown with thorn and bramble.

A 2m gap in the interior bank on the E side may represent the original entrance. A shallow gully, possibly a modern drain, runs from the N side of the site. The remains of a bank can be seen in the undergrowth S of the field wall and 10m W of the outer bank. Its purpose or extent could not be determined.

The monument is of national importance for its potential to enhance our knowledge of medieval settlement, organisation and defence. The site forms an important element within the wider medieval 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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