Treginnis walk

Porthclais Harbour, Pembrokeshire

Route details and mapDownload as a print friendly PDF
Ramsey Sound from Treheinif on the Treginnis Peninsula © Nicky Middleton-Jones

Ramsey Sound from Treheinif on the Treginnis Peninsula

Cliffs on the Treginnis Peninsula © Marilyn Smyth

Cliffs on the Treginnis Peninsula

Porthclais Harbour © Jane Mason

Porthclais Harbour

Route overview

This walk takes you over Wales’ oldest rocks - of the Pre-Cambrian era - which dominate the peninsula. They're volcanic in origin, covered in places by layers of younger, sedimentary Cambrian rocks.

Route details

See this step-by-step route marked on a map

Trail map
  • Directions
  • Route
  • Bus stop
  • Parking
  • Toilet
  • Viewpoint

Start: Porthclais Harbour, grid ref: SM741242

  1. Turn right as you leave the car park, walking up the road past high blackthorn hedges.

  2. At the crossroads, turn left (signposted Treginnis). The landscape is dominated by the igneous outcrops of Carn Llidi, Carn Trefeiddan and Penberry. As you pass Treginnis Lodge, Skomer Island comes into view to the south across St Bride's Bay.

  3. At the sign for Pencnwc Farm, turn right off the road and immediately left, following footpath sign to Porthstinian/St Justinian. Walk through a patch of scrub woodland and past a National Trust sign for Treheinif. After about 55yd (50m), go through a metal gate and follow bridleway signs around the field edge.

  4. Continue to follow the footpath out of the far corner of the field, then immediately right through a metal gate. Carn Rhosson (topped by a white pole) and the North Bishop come into view as you walk towards the sea and Ramsey Island. Turn right through a metal gate, along a track and through another metal gate onto the short section of road to St Justinian.

    Show/HideRamsey Island

    Look ahead for the spectacular island of Ramsey, whose twin peaks are the remains of long extinct volcanoes. Ramsey is separated from the mainland by the fierce currents of Ramsey Sound.

    Ramsey Sound from Treheinif on the Treginnis Peninsula © Nicky Middleton-Jones
  5. At St Justinian tour the RNLI station, if open. A new one is to be built soon in the cove immediately south of the old one. St Justinian is the start point for boat trips to Ramsey. Turn left onto the coast path, where you'll be for the rest of the walk.

  6. Along the coast path youll see a small promontory, a coastal Iron Age fort called Castell Heinif, with weathered ramparts just discernable. Continue south through two more kissing gates. After the second, the path bears right past Seal Bay look out for seal pups in late summer.

    Show/HideWales's oldest rocks

    Wales's oldest rocks - of the Pre-Cambrian era - dominate the peninsula. These are volcanic in origin, covered in places by layers of younger, sedimentary Cambrian rocks.

    Cliffs on the Treginnis Peninsula © Marilyn Smyth
  7. A steep descent past a short fenced section of cliff brings you to an open grassy area and the ruins of a 19th-century copper mine. Follow the coast path south and then east. As you bear left you can see Skomer, Midland Isle and the Marloes Peninsula in the distance.

  8. Round the corner you walk through some fine coastal heathland and down to the rocky cove of Porthlysgi, an area noted for its shipwrecks. Just east of Porthlysgi, admire the Picrite headland. Picrite is a type of basalt, another reminder of the areas volcanic origins. Follow the coast path round to Porthclais Harbour and back to the car park.

    Show/HidePorthclais harbour

    Porthclais is the only harbour between Solva and Porthgain. The cliffs and slabs to the east of the harbour entrance are a popular climbing spot. Don't miss the Kiosk in summer, for ice cream and great homemade cake.

    Porthclais Harbour © Jane Mason

End: Porthclais Harbour, grid ref: SM741242

  • Trail: Walking
  • Grade: Moderate
  • Distance: 6 miles (9.6km)
  • Time: 3 hours
  • OS Map: Landranger 157
  • Terrain:

    Moderate to rugged paths with some rocky sections. Dogs must be on leads, sheep are often on the coast path.

  • How to get here:

    By bus: Routes 342 and 411, Haverfordwest to St David’s; Puffin Shuttle 400, Solva, Marloes and Milford Haven to St David’s; Strumbe Shuttle 404, Fishguard and Newport to St David’s. Then catch Celtic Coaster shuttle bus from St David’s to Porthclais.

    By train: Haverfordwest, 20 miles (32km); Fishguard, 19 miles (30km).

    By car: 1.5 miles (2.4km) south-west from St David’s, follow signs for Porthclais. Post code SA62 6RR.

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