Porth Ysgo is a small sheltered National Trust beach at the end of the Llyn peninsula. The beach is mostly sand and shingle backed by high cliffs and looks out towards the islands of Ynys Gwylan. Very little beach is available at high tide. The waterfall of Pistyll y Gaseg is behind the beach, and is best seen after a period of heavy rain.
Limited roadside parking can be found at Grid Ref : SH212269, just off the Rhiw - Aberdaron road, from where access to the beach is a footpath along a small scenic V-shaped valley. Alternatively, parking can be found further along the lane at Ysgo farm which has an honesty box for the fee. A steep path with about 140 steps descends to the shore. Just to the east is a tiny cove of rocks and pebbles known as Porth Alum. A little further east is the delightful bay of Porth Llawenan (Grid Ref : SH213262) - a similar beach of sand and rocks, but difficult to reach (and much quieter) as the land behind is fenced off. The best access is to follow the incline down from the old winding house, scramble down to the shore wherever is easiest, and continue across the rocks (at low tide) to the beach. It's usually deserted apart from the occasional angler fishing for bass and wrasse.
Remnants of the Nant manganese mine can be seen in the valleys behind the beaches, the ore being carried down the hillside to a quay on the beach. Some of the mine entrances are accessible, but there are some steep drops inside some of these, so exploration should not be undertaken lightly or without proper equipment.
To the south-west is the islet of Maen Gwenonwy, connected to the mainland by a shingle tombolo. The beach known as Porth Cadlan is on the east side of this, and although shown on maps as sandy, it's actually all rocks and shingle. There is no path down to it, but it is possible to reach it by carefully scrambling down a very steep grassy slope and steep rocks at the bottom.