Caer Gybi Roman Fort

Caer Gybi in Holyhead contains the remains of a small Roman fortlet and naval base, whose atmospheric ruins can today be explored.

Caer Gybi Roman Fort history

Although the construction date of Caer Gybi is unknown, it is believed that it was built in the late 3rd or early 4th century. The structure was made up of three defensive walls with circular watch towers at each corner, while the fourth side fronted the sea and may have been a dock for the Roman warships that would have patrolled the area.

It is thought that Caer Gybi was constructed to defend against Irish sea raiders, and as a smaller fortlet was probably an outpost of the larger Roman fort at Segontium. It is believed that the Roman watchtower, which stood on the nearby Holyhead Mountain, served as the lookout post for Caer Gybi.

The Romans abandoned the region in the late 4th century, and by the 6th century the site had been given to Saint Cybi who founded a monastery within the walls. The medieval Church of St Cybi still stands there today.

Caer Gybi Roman Fort today

Today, visitors to Caer Gybi can still view much of the original Roman defences, with walls standing up to 4m in places and at least one original corner tower.

The architecture of Caer Gybi reflects other Roman defences of the time, many of which formed the ‘Saxon Shore’ forts, and can still be seen in places such as Portchester Castle and Pevensey Castle. The construction even mirrors Roman sites further afield, such as the well-preserved Lugo Roman Walls in northern Spain.

Getting to Caer Gybi Roman Fort

Caer Gybi Roman Fort is located in Holyhead on Anglesey in Wales, and lies virtually at the end of the A55 on the adjacent A5154 road. Holyhead train station is a 10-minute walk to the site, while a number of bus services also run into the area, with the Summer Hill stop a 4-minute walk away.