Cefn Cil-Sanws is a 461m hill above Merthyr Tydfil and below the Brecon Beacons horseshoe walk. I walked this along with Garn Ddu following the route above and the hill is well worth walking, being topped by a trig point and a cairn / stone shelter.
The walk from Garn Ddu is pleasant enough, especially after you pick up an established track.
The track takes you to a gate into the final field that the summit is in. There are various tracks here, but most of the ones towards the summit appear to be little sheep trails.
The trig point is lower than the cairn and the little hump slightly to the right. Views towards Merthyr Tydfil are good, as well as down towards Mynydd Aberdare.
This is a really good hill, with good views and good points of interest. A really nice little walk and very peaceful compared to the mountains nearby.