1. (00km) START with your back to the Neuadd Arms (GR 879 467). TURN R and take the Abergwesyn road 7km (4.4m) to TURN L on marked diversion up RU PP/drive towards the old Llwynderw Hotel. KEEP L past the hotel to a T junction. KEEP L and go through the LH gate and follow the muddy track (with the hedge along the RHS) up to the 2nd gate. Go SO through the gate and follow a muddy field track which soon descends gently to another gate just before a wide stream (GR 642 517).
2. (8.6km/5.3m) Go through the ford and follow the track as it swings to the left and then right up the hill towards the fence line. Climb up the RHS of the fence line and when you reach the top FORK L, still following the fence line (now on unclassified track) when you soon start to descend. As this track becomes steeper look out for a narrow track to the right by a tree, TURN R (don't go all the way down to the stream). This track winds around the head of a little valley, rejoins the bridleway and undulates for about 2.5km (1.6m) until it descends into a valley with the road ahead. When the track levels out it is best to cross the stream where convenient (it's eroded away on the RHS) and head for the road.
3. (11.8km/7.3m) At the road TURN L and begin a steady climb around Llyn Brianne (good views over the lake) for about 3.4km (2.1 m). You eventually stop climbing and the road descends to a forest road junction on a bend 15.2km (9.4m) (GR 806 490). KEEP L through the barrier, over cattle grid and start a long climb up forest road.
At the next junction TURN R 18.2km.
At the next set of junctions KEEP SO 19km.
At the next junction TURN R 19.6km.
At the next junction TURN L 20.4km.
At the next junction TURN R 21.4km.
After the next LH bend you start a long, fast descent down the valley. At the bottom go SO through the gate and to the next bend.
4. (23.7km/14.7m) TURN R down a muddy then stony bridleway track (sign posted) to a ford. Cross the ford, go through the gate and climb the stony track to the lane at Dinas. TURN R and descend to the church at old Llanwrtyd, swing R then L around the church and cross the bridge and follow the road around to the R back to Llanwrtyd Wells.