The stones in Penrhos Feilw were probably set in the Bronze Age, around 2000-1500 BC, but it is not known by who and for what purpose it were built.
The stones are about 3 meters high, 3 meters wide at the base, only 20 cm thick and the shapes are close to each other. They were laid out on an open grassy spot between two low hills, along their long axis towards the north-east, south-west. Most likely, they were not part of the stone circle. Reports of finding a small ossuary (cist) near them are not confirmed.
Website stone-circles.org.uk, Penrhos Feilw Bronze Age Standing Stones.
Website wikipedia.org, Penrhos Feilw Standing Stones.