Maen Ceti (also known as Arthurs Stone) is a neolthic Portal Burial Chamber just north of the ridge summit of Cefn Bryn in the Gower Peninsula, Wales (Welsh: Penrhyn Gŵyr, Cymru). It has a very long 25 ton capstone, part of which is split away and lies next to the main structure. The site is reached by continuing west along the A4118 and then taking the minor road on your right towards Reynoldston. Then take the road east toward a small parking area on the north side of the road and the site is along a pathway.