Caer y Twr, Holyhead Mountain Watch Tower

Caer y Twr, Holyhead Mountain Watch Tower

Caer y Twr is a late Roman watchtower built within the remains of an Iron Age hill fort on the east slope of Holyhead Mountain.

Holyhead Mountain is the highest hill on Anglesey (calling it a mountain is really stretching things a bit!) and the watch tower would have afforded wonderful views over the Roman harbour of Holyhead to the east.

The remains are now very scant, but the walls of the fort can still be traced. Sections of the perimeter rampart stand to 3 metres and stones found during excavations of the tower footings suggest that it was built between the 2nd and 4th century AD.

The best-preserved part of the watch tower lie immediately beside the summit cairn, on the highest point of Holyhead Mountain.

On the west slope of the mountain, below Caer y Twr, is a sizeable hut circle settlement which may have been in use at the same time as the fort.

The watchtower foundation walls

Getting There

You can reach the summit of Holyhead Mountain from South Stack, but we took the footpath from Breakwater Country Park. The path follows the Anglesey Coastal Trail as it skirts the headland to North Stack before a minor trail branches off and heads directly for the summit.

The going is rough but the footpath is well-maintained in most places and should not present any difficulties for a reasonable fit person. I managed it using crutches, but I like a challenge!

The walk took us about 80 minutes to the summit, but we stopped frequently to take photos and to study our OS map. And, of course, there were those crutches ... The descent took much less time; about 45 minutes, though we took a steeper, more direct route on our way back.