Caer Gybi

Caer Gybi stands in the middle of Holyhead on Anglesey, a small fortlet built by the Romans in the 3rd or 4th century. It was a naval base to guard the west coast from Irish sea-raiders and may have worked with a watch tower on Holyhead Mountain. The fort had three high stone walls with round towers at each corner and a quay along the seaward side. After the Romans left, King Maelgwn Gwynedd gave the site to Saint Cybi, who made it into a monastery in the 6th century. The fort’s herringbone-patterned walls rise four metres and are one and a half metres thick. One corner tower still stands nearly eight metres tall, though its top may have been rebuilt in the Middle Ages. Outside the northern wall an excavation found another Roman building joined to a tower, built in the same way. The Church of St Cybi now occupies the centre of the old fort, and beside it is a small chapel said to cover the saint’s grave. Visitors walk past the tall north-east tower and see the thick stone curtains of the other walls. Inside the churchyard the detached chapel marks the reputed burial place of Saint Cybi. From the fort the mountain watch tower is visible on the skyline, and the sea lies just beyond the old quay site. The remains show how the Romans organised a defended base in a busy port town.