Description

The monument consists of the remains of a Roman fort. It is sub-rectangular and measures approximately 75m by 45m. The interior is occupied by St Cybi's church and associated graveyard.

The fort lies on a low cliff which would originally have fronted the shore; the east side of the fort which faces the shore is open and there is evidence to show that the north and south walls once continued east towards the water's edge. The remaining part of the fort on top of the cliff occupies 0.32ha; the walls are about 4m high and 1.5m thick. The north wall is the best preserved and shows details of a rampart walk and parapet, the former being about 1m wide. Two rows of putlog holes are also visible, the upper row being 1.5m above the lower. A narrow entrance in the centre of this wall is probably a late insertion. A car park occupies the area outside the north wall. The church tower is built against the west wall on the inside of the fort, whereas on the outside the south part has been built against and the north part is free-standing. The south wall is also largely built against, but in the centre there is a fine double arched entrance which, although rebuilt, is probably original.

There was originally a tower at each of the four corners. The south west tower is mostly destroyed and hidden by modern buildings. The north east and south east towers have been largely rebuilt in late medieval or modern times, though they are Roman at the base. The north west tower survives in its original form. The foundations of the north east tower start at the base of the cliff and the remains of a wall running east are bonded into this tower. The east side is a fairly level cliff face supplemented with a stone retaining wall, which contains a relieving arch at the south end. A modern churchyard wall stands on top of the cliff.

The position of this site on a low sea-side cliff, together with the suggestion of an enclosed quay, and its similarity with Roman coastal forts in general, have given rise to its interpretation as a late Roman coastal fort. Although there is no direct dating evidence from the site, indications from excavations on Roman forts elsewhere in Wales - notably at Cardiff, Loughor and Neath - have demonstrated a definite pattern of late third-century coastal defence.

As part of the late Roman coastal defence system the fort was linked to the signal stations on Holyhead Mountain and Carmel Head. Specific significant views from the fort when built would therefore have been to the west to Holyhead Mountain and to the north-north-east to Carmel Head along with the general view across Holyhead Bay, an arc from northwest to north-north-east.

The monument is of national importance for its potential to enhance our knowledge of Roman military organisation. The monument forms an important element within the wider context of the Roman occupation of Wales and the structures may contain well preserved archaeological evidence concerning chronology, layout and building techniques.

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

Source: Cadw