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Caer y Twr Roman Watchtower

Iron Age settlement in a spectacular mountaintop location

Perched at the summit of Holyhead Mountain with expansive views in all directions, it’s easy to see why our Iron Age ancestors chose this spot. The rampart walls still stand 10ft/3m high and 14ft/4m thick in places, merging with the mountain’s rocky terrain to create what must have been an imposing fortification. The remains of the walls’ original internal walkway and narrow, funnelled entrance, set within a deep rocky gully, can still be seen today.

Though the massive enclosure circles an area of around 17 acres/6.9ha, the only structure found inside is the ruin of a later Roman watchtower and signal station, possibly linked to the nearby coastal fort at Caer Gybi.

Opening times & prices

Opening times

1st April - 31st March Open all year

Open all year — during reasonable daylight hours

Visitor information

Dogs welcome icon

Dogs welcome

Walking difficulty icon

Walking difficulty

Terrain: Level 4 – Strenuous 

Drone policy icon

Drone policy

No smoking icon

No smoking

Health & Safety icon

Health & Safety

Care and attention must be paid when visiting this monument. It will be regularly exposed to the natural elements and may be slippery or muddy underfoot.

Appropriate footwear for the season and type of monument must be considered prior to your visit. Please only attend during the set opening hours, these have been chosen for your safety i.e. appropriate level of lighting.

Many of our monuments are located at areas of height, attention must also be paid therefore to the surrounding areas, ditches and moats when visiting.

Guardrails have been installed to prevent access to any areas of the site that we have deemed as dangerous or to prevent falls in specific areas. Please do not climb over or through any fixed installation.

Any handrail provided should be used to help you safely navigate historic steps, as these may be uneven and may be of different height.

As with all ancient monuments there is always a risk of stones being dislodged in bad weather, however, we manage this through extensive monitoring. 

Climbing may result in serious injury

There are several wild plants and flowers, although these are great pollinators, they may be poisonous to visitors and animals, we strongly advise you not to touch or allow dogs to eat any vegetation.

There may be shared access or neighbouring farmland that may involve the presence of grazing cattle or farm animals.

Please watch our health & safety film before visiting Cadw sites.

Iechyd a Diogelwch / Health and Safety

Please report any anti-social behaviour such as climbing, setting fires, graffiti etc. to CadwAccidentsReports@gov.wales

The following signs can be found around the site at key areas of risk, please pay attention where appropriate.

Slippery or uneven surfaces icon

Slippery or uneven surfaces

Falls from height icon

Falls from height

Directions

Google Map
Road: On Holyhead Mountain, 13/4m (2.8km) W of Holyhead. Car parks at the bottom of the mountain near South Stack or Breakwater Country Park (pay and display).
Rail: Holyhead 2m (3.2km)

Grid Ref: SH219829. Lat/Lon: 53.3132, -4.6754

what3words: ///steady.sleep.shots

For further information, please contact: Traveline Cymru on 0800 464 0000 or National Rail Enquiries on 03457 48 49 50.

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