Caer y Twr

Caer y Twr is a Roman fortification on Holyhead Mountain in Trearddur with stone ramparts running along the northern and eastern sides. These walls stand about three meters high and show how Roman military builders adapted their defenses to this hilltop location.

Archaeological excavations revealed the remains of a Roman tower that stood on the site between the second and fourth centuries during the Roman occupation. This timeframe shows how long Roman military forces maintained a presence in this part of Britain.

The name Caer y Twr comes from Welsh and means 'fort of the pile'. This naming reflects the Welsh language heritage that remains central to life on Anglesey today.

Reaching the fort means climbing steep, narrow paths from the eastern side of Holyhead Mountain, where parking is limited near local houses. Wear sturdy shoes and bring weather protection, as the mountain paths are exposed and can be windy or wet.

The fort sits in a strategic location with views toward the Isle of Man, suggesting it may have been used to watch maritime traffic in the region. This positioning allowed Roman occupiers to observe sea activity from a great distance.

Location: Trearddur

Website: https://cadw.gov.wales/visit/places-to-visit/caer-y-twr

GPS coordinates: 53.31410,-4.67420

Latest update: December 14, 2025 16:43