Mynydd Preseli

Half Day + Walk

DISTANCE/DURATION: 5.6 miles (9.0 km) 3 hours.
PUBLIC TRANSPORT: Service bus Mynachlogddu 345.
CHARACTER: Rugged moorland and mire, livestock, gradients range 200-360m, 2.6 Km walking on minor road.
LOOK OUT FOR: Carn Menyn source of spotted dolerite/bluestones, Bedd Arthur Burial Chamber and Waldo’s Memorial.
CAUTION: Path not waymarked on open hill.

Take in the sights of the famous Preseli Hills.

Composed of hard Ordovician shale and mudstone compressed into slates with scattered fragments of rhyolite and dolerite – the famous bluestone that forms the inner ring of Stonehenge – the Preseli Hills are the highest hills in Pembrokeshire.

The crag of Carn Menyn is the source of the Stonehenge pillars and nearby Bedd Arthur is the Preseli’s own, rather unusual, eye-shaped stone circle.

There’s a memorial to Welsh language poet Waldo Williams at Mynachlogddu.

If you’re lucky to get clear weather, you’ll be able to see north to the Lleyn peninsula and west to the hills of Co. Wicklow in Ireland.

Keep your eyes peeled on the hill though as the bird life, particularly in the winter months, can be remarkable with living clouds of starlings congregating to roost there.

Also look out for hunting buzzards and sparrowhawks. In the spring ring ouzel and snow bunting are common migrants.

Much of the upland is boggy and, as a result, very acidic so you can find rare acid tolerant plants like fir clubmoss, liverwort, ferns and orchids with insects like the marsh fritillary butterfly and the southern damselfly.

Heather carpets the drier heathland in late summer look out for buzzards, kestrels, curlews, ravens and skylarks.

Find this Walk

Grid ref: SN105325


  • Enjoy the countryside and respect its life and work
  • Guard against all risk of fire
  • Leave gates and property as you find them
  • Keep your dogs under close control
  • Keep to public paths across farmland
  • Take your litter home