Holyhead Mountain (Mynydd Tŵr) is the highest point on Anglesey at about 220 m. Visit Anglesey's circular walk starts at Breakwater Country Park and heads out to North Stack, over the mountain to South Stack, past Ellin's Tower and the prehistoric hut circles, then along the coast path to Porth Dafarch before returning over farmland and heath.
A steep side path climbs to the summit, wrapped in the stone ramparts of Caer y Tŵr, an Iron Age enclosure of about 17 acres. The only building inside is the base of a later Roman watchtower. Cadw cares for the hillfort, which is free and open in daylight.
Good to know
Visit Anglesey grades the walk challenging: expect steep climbs, rough and possibly boggy paths, clifftop sections, kissing gates, a ladder stile and two stretches of road without pavement.
Route map: Visit Anglesey: Holyhead Mountain circular walk
Where to go
Start from the car park at Breakwater Country Park, Holyhead. Caer y Tŵr is on the summit (Cadw grid reference SH219829, what3words ///steady.sleep.shots).
Opening times
Caer y Tŵr: open all year during reasonable daylight hours
Parking
Council car park at Breakwater Country Park (charges apply; annual season ticket available from the council). Cadw also suggests parking near South Stack (RSPB pay and display) to reach the summit.
Public transport
Holyhead has a railway station. Bus 22 stops at Maes y Mynydd, Llaingoch, a short walk from Breakwater Country Park (Visit Anglesey).
Walk
About 20.4 km / 12.7 miles circular
Challenging
Breakwater Country Park car park, Holyhead (LL65 1YG)
Step-free access
No, steps or rough ground
Access details
Visit Anglesey grades the walk challenging: steep, on-road in places and possibly boggy. Cadw grades Caer y Tŵr Level 4 (strenuous); exposed, slippery or muddy, with height and steep drops.
Facilities
Café at Breakwater Country Park (Caffi'r Parc) and at the RSPB South Stack visitor centre; toilets at both
Dog rules
Visit Anglesey lists dogs as welcome on the walk, and Cadw says dogs are welcome at Caer y Tŵr. Grazing animals may be present.
