Porth y Rhaw (last syllable rhymes with 'cow') is a small inlet on the north side of St Brides Bay. It is mostly rocks and pebbles with some sand on a very low tide. The cliffs are of dark mudstones and sandstones. Parking for about 6 or 7 cars can be found on the lane to Nine Wells caravan and camping site - turn off the St Davids road just after the 'Nine Wells' sign where the road dips. The parking area is about 40 yards down on the left just after the cottage at Grid Ref: SM787248 (Lat : 51.8780°N, Lon : 5.2163°W). From here a footpath follows the valley down to the beach. It's probably a good place for snorkelling but not much else. To the east is the cove of Aber Llong which has more sand and the rusting remains of a shipwreck visible at low tide. This beach can be accessed by walking (with great care) down a steep scree slope and rocks on the eastern side.
The photo was taken an hour after low tide.