Ancient Monuments

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Llangibby Castle (Castell Tregrug)

A Scheduled Monument in Llangybi, Monmouthshire (Sir Fynwy)

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Latitude: 51.6718 / 51°40'18"N

Longitude: -2.9211 / 2°55'16"W

OS Eastings: 336397

OS Northings: 197408

OS Grid: ST363974

Mapcode National: GBR J8.5ZY0

Mapcode Global: VH7B1.B72Q

Entry Name: Llangibby Castle (Castell Tregrug)

Scheduled Date: 5 September 1950

Source: Cadw

Source ID: 365

Cadw Legacy ID: MM109

Schedule Class: Defence

Category: Castle

Period: Medieval

County: Monmouthshire (Sir Fynwy)

Community: Llangybi

Traditional County: Monmouthshire


The monument consists of the remains of a castle, dating to the medieval period. The castle was built by the De Clare family in the 13th century, but is thought to have been unfinished when Gilbert de Clare V was killed at Bannockburn in 1314. The site consists of a large oblong bailey, 160m long by 80m wide, surrounded by a curtain wall that is largely complete to battlement level. There is an entrance into the bailey at the E end of the site. The entrance is 3.5m wide and has the remains of round towers on either side - the N round tower only survives as a curved wall, while the S tower is complete and stands to a height of 5m. The walls of the tower are 3m thick. The curtain wall on the E side survives in short stretches, one to the N of the entrance and three to the S. These sections of curtain wall stand to between 1.2m and 5m high on the inside, and up to 2m higher on the outside, and retain many original facing stones. On the S side of the site, there is a short stretch of curtain wall, 12m long and 3m high, at the E end. To the W of this section of wall is a 50m wide gap before a long stretch of curtain wall. In the gap there is a low scarp. The long section of walling is 30m long and 3.5m high, and has putlog holes for supporting timber buildings on its inside. In the SW corner of the bailey are the remains of a large tower, 6m high on the outside, with a large arched opening on the S side and the remains of a spiral staircase. Adjacent to the tower are the remains of a series of room. To the N of this tower is a 20m long, 2.5m wide entrance passage, with standing walls 3.5m high. To the N of the entrance is a round tower, 3.5m high, with a room behind it. A well-preserved doorway survives to the N of the tower. It is 1.8m wide and has a dressed stone wall behind it. To the N of the tower the curtain wall becomes more ruinous and the peters out. In the NW corner are the remains of a rectangular keep with towers at its corners. The tower in the SW corner is massive, 6m high with facing stones surviving for much of its height. The NW corner tower is 5.5m high with most of the facing stones missing. Large sections of fallen walling lie on the ground to the W of the tower. Inside the W end of the rectangular keep are two large arches with two smaller ones on either side. On the S side there are portions of ashlared vaulting on the roof of the room. At the E end there is a large central arch through the keep wall, with round towers on either side, each with an arch into it. The walls are up to 3.5m high and retain much of their faced stone. There is a further vaulted roof in the NE tower, which has a six-sided interior and two steps on the SE side. On the N side of the castle the curtain wall is continuous, 3m high on the inside and 4m high on the outside. There are putlog holes in the N wall and the stonework is in good condition. In the centre of the N side are the remains of a round tower standing 2m high with 2m thick walls. There are gaps in the middle on each side. The curtain wall ends abruptly at the NE corner of the castle.

On the W side of the castle the ground drops steeply down to a deep ditch, part of which forms a sheer rock face 3m high. Outside the ditch is a narrow berm and a bank, varying in height between 1.6m and 3m. At the S end of the bank there is a gap for a modern track, after which is continues along the S side of the site. On the N side of the castle the ground drops sharply away.

The monument is of national importance for its potential to enhance our knowledge of medieval defensive practices. The monument is well-preserved and an important relic of the medieval landscape. It retains significant archaeological potential, with a strong probability of the presence of both structural evidence and intact associated 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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