Caer Gybi Roman Fort

In the centre of Holyhead, the parish church of St Cybi sits inside the walls of a small late-Roman fort built around AD 300 as a defence against Irish sea raiders. Three of the four corner towers and a long stretch of curtain wall survive, complete with the irregular Roman bonding-courses of stone tiles. It is one of only a handful of Roman forts in Britain where the walls are still standing to anything like their original height.

The fort was given to St Cybi, a 6th-century Welsh missionary, after the Romans left, and the medieval church grew up inside the walls — the name "Caer Gybi" simply means "Cybi's Fort." The result is the unusual experience of walking through a Roman gate to reach a medieval church.

things to do sight architecture
A story
Three of the four corner towers of the Roman fort still stand, with their masonry of small squared stones rising directly out of the medieval graveyard. Almost nowhere else in Roman Britain do you walk through a fortification this complete without paying an entrance fee or even crossing a fence.