(S/E) To reach the start follow the A4212 northwest from Bala to just before where the B4391 heads north to Ffestiniog. Turn left down a minor road for about a mile. On your left is large area of waste ground (Grid ref. SH831392) with more than ample space for parking. After parking continue along the lane in an easterly direction for a further mile passing a number of houses on the way. Just after Pant-yr-Hedydd take the rising grassy track (Grid ref. 845395) that initially heads south west.
(1) The track turns to head southeast and levels off with the waters of Llyn Arenig Fawr soon coming into view. Continue on the track until you see a small building near the dam outflow. Turn right down a path and through a gate at the rear of this building. Cross the outflow stream and continue ahead following the path that rises along the crest of ridge with the reservoir on your right. The climb is steady and the path easy to follow and you soon reach a fence. Cross this and continue in the same approximate direction until a fence is approached at an acute angle. Cross this fence where convenient and make sure you follow the path, which in places is less than obvious.
(2) This path does not climb directly onto the ridge ahead but trends left and contours across the southeastern flank of Arenig Fawr gradually climbing. As you get nearer to the area beneath the summit look out for a solitary post located up the slope. This marks the best route of ascent and soon you will reach the summit cone. Besides the obligatory OS trig point there is a wind shelter and a memorial to a bomber crew that crashed here during World War II. The view is superb especially to the north. On a clear day you can see all the high mountains of Snowdonia including Snowdon, Crib Goch, the Glyders, Tryfan and the Carneddau.
(3) Arenig Fawr has a number of clearly defined ridges and it is important for the purposes of this route to choose the right one! The easiest method of navigation is to leave the summit in a northeasterly direction following the fence which should be on your left. There is a path and you need to continue beside the fence for nearly a mile. Ahead lie some fairly severe crags and these must be avoided. The safest way to do this is to cross the fence line (grid ref. 834380) and drop down into the wide cwm on your left.
The path becomes less obvious and you will probably find yourself picking your way along sheep trods and other breaks in the heather. However the key to this descent is to locate the stream and follow it down towards the valley below. There is a path (of sorts) which leads all the way down to a grassy track that runs parallel to the lane. Once this reached turn right and you will be back at the parking area in a few minutes(S/E).
