Craig y Llyn
- Not to be confused with the like-named subsidiary summit of Cadair Idris
| Craig y Llyn | |
| Glamorgan | |
|---|---|
 Craig y Llyn | |
| Summit: | 1,969 feet SN906031 |
Craig y Llyn is a mountain in Glamorgan. It rises up on the west side of the upper Cynon Valley in the parish of Rhigos. It is the highest point in Glamorgan.
The name "Craig y Llyn" means "Lake cliff", referring to the cliffs of its steep northern escarpment which overlook Llyn Fawr.
Craig y Llyn is found in the parish of Rhigos. The village of Rhigos stands on the northern side of the mountain, and Craig y Llyn is commonly known as the Rhigos Mountain after the village.
The mountain is covered by forestry, except for the steep north and northeast faces, and is crowned with a trig point. Several footpaths cross near the summit of the hill, including the Coed Morgannwg Way.
Geology
The hill is composed of a thick sequence of sandstones and mudstones assigned to the South Wales Coal Measures. The summit plateau is formed from the Pennant Sandstone of the Upper Coal Measures. The two cwms on its northern flanks which shelter Llyn Fach and Llyn Fawr are of glacial origin. A landslipped mass of rock lies above the western end of the latter lake.
