This is a tough walk with plenty of ascent. The distance and height gain is quoted from Maen-llwyd-isaf (Sat Nav LL55 4SR) Llanberis. A total route of 12 miles, it will take a full day, good mountain boots and clothing is required. Use OS map OL17 and a compass. A good quality mountain day walking.
After parking, head downhill towards Llanberis for a few metres and take the signed path on your right. This leads easily into a lane, which should be followed southwards to Brithdir. Staying on this path climb steadily to Bwlch Maesgwm. Turn left and climb more steeply to the summit of Moel Cynghorion.
Descend southeast off the summit to a further col – Bwlch Cwm Brwynog – where you will locate two stiles in the fence. The first of these will be used in the return route and the second is the one to cross. This leads to a narrow path that descends into Cwm Brwynog before climbing through a boulder field to Llyn Du’r Arddu. At times the route is hard to follow but it is there and with some persistence you will arrive at the shores of the tarn.
Follow the northern shore of the tarn and pick up a stream that comes down from near Clogwyn Station. Follow this for a short way over easy ground before scrambling up the grassy slope strewn with boulders to reach the Llanberis path. Turn right onto the main path and head for the summit of Snowdon.
Retrace your steps from the summit past Bwlch Glas, where the path to Pen-y-pass descends right and take the next left fork. This is the Snowdon Ranger Path. Follow this as it descends across the top of Clogwyn Du’r Arddu to Bwlch Cwm Brwynog. Climb up grass to true Col and locate the two stiles detailed previously in the text. Cross the left hand stile and join a clear path that traverses across the eastern flank of Moel Cynghorion.
The path twists and turns heading north before turning west near the derelict farmstead of Hella-fawr. A wall with a ladder stile will be seen on your right. Ignore this stile and continue, with the wall on your right, to reach Hella-fain, another derelict farmstead. Cross the footbridge near the buildings and follow the right of way towards Brithdir, although you might find the actual route hard to follow. At Brithdir you join the outward route, which is followed back to the start.