This site is now open to view or visit.
In line with Welsh Government advice and guidance, we have started to reopen a selection of our unstaffed heritage sites in a safe and controlled way — for the benefit of local communities.
We are pleased to announce that this monument is now open and is free to view or visit with no pre-booking required. Please adhere to our new visitation guidelines, act responsibly and be respectful towards the site and its local area at all times.
Site opening times, parking and other available facilities at our reopened sites may have changed. Please check this site’s webpage carefully for specific updates.
For further information on what to expect and how to stay safe during your visit, please read our FAQs page.
Northern military outpost in a strategic coastal location
Dating back to the 3rd century, Caer Gybi’s position on low cliffs overlooking the sea suggests it was part of a coastal network of defences, possibly linked to the late Roman watchtower at Caer y Twr on the summit of Holyhead Mountain.
The walls of this rectangular fort are extremely well-preserved, standing up to 13ft/4m high and 5ft/1.5m thick. You can also see remains of four corner towers. Occupying a vantage point above the harbour, the 26ft/7.9m north-east tower is the most prominent, though the top section is a later rebuild possibly dating to the medieval period.
For further information, please contact: Traveline Cymru on 0800 464 0000 or National Rail Enquiries on 03457 48 49 50.