Craig y Llyn is a Marilyn of 600 m in Neath Port Talbot. It is also on the county tops list, as the highest point of its historic county.
Its closest neighbour in this register, Fan Nedd, is 15.3 km away. All four of its nearest neighbours are higher, up to Fan Brycheiniog – Twr y Fan Foel at 802.5 m. It is the lowest of the 56 hills profiled in Wales. All four of its nearest neighbours lie to the north, so it stands at the southern edge of its group. On the Marilyns height ladder it sits between Black Combe (600.2 m) and Blake Fell (572.6 m). The summit is marked by a trig point.
