St Cybi’s Church and Caer Gybi Roman Fort
A medieval church standing inside the walls of a late Roman fort in the centre of Holyhead. The fort walls are free to see at any reasonable time.
In the middle of Holyhead, overlooking the harbour, St Cybi’s Church stands inside Caer Gybi, a small late Roman fort. The fort is rectangular, with walls up to 4 metres high and remains of four corner towers. It was probably part of a coastal defence network, possibly linked to the Roman watchtower at Caer y Tŵr on Holyhead Mountain.
St Cybi is said to have founded a church here around 540. The present building dates from the 13th to 16th centuries, and the small 14th-century chapel of Eglwys y Bedd stands in the churchyard. The church reopened in 2026 after a major restoration.
Good to know
Cadw grades the fort as accessible terrain, and dogs are welcome. The church has its own opening times, so check before you travel if you want to see inside.