Alongside the A4212 from Trawsfynydd to Bala runs the old disused railway line, a section of which has kindly been made in to a permissive footpath. We took the opportunity of a fine January morning to explore the section through Cwm Prysor, with its fine old viaduct being the centre of attraction. A small amount of parking is available at the side of the main road, see map below. The walk is a straight walk & return that is mainly level and which can be extended or shortened to suit your wishes.

Parts of the walk can be quite wet despite following the old rail line but these damp cuttings offer much in the way of mossy foliage & trickling water.

As one approaches the viaduct it is possible to view from the left side of the line. A little closer and one can carefully drop down the forest edge of the viaduct to join the North – South FP right of way (which barely exists anymore). I can’t say that this is an ‘official’ or recommended action but it does give access to more dramatic views of the viaduct.

The highest arch of the viaduct is 105 feet tall, certainly enough that perspective corrections were needed on my HDR image stack above! There are more photos taken from this lower footpath in the gallery at the end of this post.
Heading back up to the rail line, we can now cross the viaduct, taking care not to lean too firmly against the old fencing at the edge of the precipice.

On our previous walk, over Arenig Fawr, we had spotted the viaduct from the summit; this prompted our exploration of Cwm Prysor a few days later. Don’t miss the view back to Arenig Fawr from on the viaduct..

Having crossed the viaduct, one can now continue westwards along the old line. It is possible to take diversions in to the hills via paths and open access land or to reach as far as Trawsfynydd; check your maps. The views open up westwards, towards the Rhinogs.

Once you’ve walked far enough for your liking, just retrace your steps back to the start. On our return walk I paused just before reaching the viaduct to take this infra-red photograph of the scene, hoping to give the viaduct view an old but timeless feel ..

It’s a great walk for a fine day. In spring & summer the old line will be busy with birds & butterflies, in winter it’s a peaceful walk with great views.
Map:
Gallery (click on any image to bring it up as a slideshow with exif data):
Morning light floods in to the forestry under the arches of Cwm Prysor Viaduct Arenig Fawr as viewed from Cwm Prysor viaduct. Cwm Prysor viaduct from the forestry From the old Trawsfynydd to Bala rail line Cwm Prysor – Looking north at the viaduct from the footbridge. Looking west along the old railway line The old Trawsfynydd – Bala viaduct at Cwm Prysor. Photographed in infra-red. The view approaching the viaduct from the east. Icy clutching fingers protrude from the cutting walls The view westward along Cwm Prysor viaduct One of the old rail line cuttings