Snowdonia
SH645314 There is pay parking near the road head in Cwm Bychan. The path (a packhorse track) leads straight from Cwm Bychan and is signposted for clarity. It climbs steadily south up through the trees to emerge at a stream crossing.
SH648308 Cross the stream and take the path that trends south-east. The Roman Steps path is an ancient communications link that probably pre-dates Roman activity. It was an important military road used by Edward I when his forces occupied Harlech Castle in the 1280s. The path is constructed with large slabs and is easy to follow – take it all the way to the top of Bwlch Tyddiad.
SH658299 The top of the pass is in a narrow col, if you have time it’s worth making a short out and back climb up the north side to get an impressive overview of it. Continue over Bwlch Tyddiad on the main path and descend for about 100m to a narrow path on the right.
SH660299 Take the narrow path and follow it south then south-west as it climbs to the hanging corrie occupied by Llyn Du. Surrounded by rock ramparts the llyn is both dramatic and sheltered, and is a great place to explore or have a bit of a break. The route heads around the south side of Llyn Du and then heads west until you encounter a wall. Handrail the wall south-south-west for about 200m until a path breaks off left. SH652291 The path climbs east and heads directly for the summit of Rhinog Fawr.
SH656289
Rhinog Fawr is a particularly fine summit with rocky outcrops and a dramatically positioned trig point. The views are extensive and are wide ranging, both of the main bulk of the Snowdonia mountains, and also of the closer peaks and the coastal plain and estuaries. To avoid problems with encountering crags on your walk, the best descent is to retrace your steps back to Cwm Bychan via the wall-side path, Llyn Du and Bwlch Tyddiad.