Sarn Helen above Manod Quarry

Trawsfynydd to Dolwyddelan

Distance: 21km.

Grade: fairly difficult, mostly on good tracks, some boggy sections and open moorland.

Transport links: The Bangor-Aberystwyth bus passes Trawsfynydd on the A470. Dolwyddelan has trains and buses to Llandudno and Blaenau Ffestiniog.

See for details.

To find the Roman road again after Trawsfynydd, leave the village by the road to the north.

At SH 70822 36120, cross the main road and follow the green track (signposted as a footpath). This curves round to the left and becomes a path round the edge of the fields. Cross the wall by a ladder of projecting stone slabs and go past the ruined farm then through a gate.

The path becomes a hollow lane between walls and rows of trees, leading downhill. At SH 70922 36685, cross a small stream and go up the other side of the valley. Follow the footpath sign through a wooden gate and continue round the edge of the fields.

At SH 70965 37148 a lane joins from the right. Bear left, follow the footpath sign over the old packhorse bridge and up the other side.

At SH 70890 37270 the top of the hollow lane is nearly at the main road, but go through the gate and turn right along a minor road. This road bends left then right to cross a bridge over the disused railway line. A little further on, an interpretative board describes some of the local paths and features and a waymarked footpath to the left leads you to the fort. (You could reach this point by following the line of the Roman road from the tile kilns, turning sharp left to visit Trawsfynydd if necessary then rejoining the line of the road past Llwyn-crwn Farm.)

At SH 70555 38148, the track crosses a bridge and bears up to the right. Go through a gate and bear up to the right again towards a ruined stone building, along a hollow trail at the edge of the field and under the line of pylons, passing between the pylon and the ruined stone building. The mound of Tomen-y-Mur Castle is above you to the left: but do not go towards it yet. Go through a broken gate. 

At about SH 70777 38565 you have to jump across the stream. You may be able to spot the Roman bridge abutment at SH70723852, and there are foundations of Roman buildings to either side. Continue along the track to explore the fort of Tomen-y-Mur (see below for details).

Leave the fort along the track past the amphitheatre and turn right on a minor road. This bears left round the edge of the forest and heads towards the mast, paralleling the line of the Roman road. 

At SH 70960 39703 the metalled road bends slightly to the left and paths are marked to the left and right and straight on. There have been changes in the roads and paths since we walked this in 2005 and we need to recheck this section.

If you follow the signpost straight ahead you can cut down to a stile (badly-decayed in 2005) into the forest at SH 71332 39973. This is the route recommended in the Sarn Helen guide book, but it is heavily overgrown and boggy. You may prefer to keep to the metalled road through the forest and continue straight ahead on a forest road at SH 71370 40185 when the metalled road turns sharply to the left.

At SH 71557 40243 the footpath crosses the forest road. Here you have to take the footpath and walk down towards a house. The right of way goes through the garden at about SH 71635 40305, continues across the next field towards the forest - then vanishes. It should be possible to walk down the drive from the house. At SH 71640 40538 a track joins from the right. Keep to the left: from here the drive becomes a right of way again. At SH 71682 40690 take the track to the left. The right of way goes to the right of the farmhouse at Bryn-saeth and across the field from SH 71622 40748 to SH 71545 40820, but it may be better to keep on the farm lane and walk down to Bont-newydd.

Also to your left is the farm called Llech Goronwy, Gronw’s Stone, after an episode in the Welsh legend of Lleu and Blodeuedd. The farmer at Bryn-saeth told us that if we were interested in history we should look at a stone in the field above his farm. We went through the gate to the left just after the farmhouse and crossed to the top right of the field. There in the far corner, on the bank of the stream, was Llech Gronw, the standing stone of the legend in the Mabinogion, with the hole driven through it by Lleu in his rage and grief.

Continue down the track to the little village of Bont-newydd, across the bridge over the Cynfal and up the side road to the right. A footpath is marked on the map along the line of Sarn Helen but it is blocked in several places and difficult to follow.

From this point it should be possible to cut down into Llan Ffestiniog and Blaenau Ffestiniog, capital of the Welsh slate industry. Both have shops and accommodation. Blaenau Ffestiniog has two railway stations, an underground slate mine for wet days and the amazing Siop Llyfrau'r Hen Bost. This second-hand bookshop in the old post office (tel: 01766.831802) will break your back but not your bank!

At SH 72265 42328, take the stony track north past the waterworks buildings. You are now back on the line of Sarn Helen. Ahead of you is the Iron Age hill-fort of Bryn y Castell, and away to the right over the spur is Llyn y Morwynion, the grave of Blodeuedd’s maidens.

At SH 72537 42753, the paths divide in front of Bryn y Castell. Frances Lynch recommends taking the path to the right then bearing left and climbing the fort from the north, past the post-Roman round houses. The paths rejoin north-west of the fort at SH 72537 42753. Cross the footbridge across the Gamallt. Just downstream of this is the old farm of Hafod-ysbyty, the summer hospice.

The path goes up from the bridge along a fairly well-marked hollow trail. Below you are the slate workings south of Blaenau Ffestiniog and the road up to Manod Quarry, one of the few surviving slate works: and all around you are panoramic views over the mountains. Pass between two crags to skirt round to the right of Carreg y Fran. There are more hut circles and a settlement site on the southern slopes of the crags to your right. At SH 73690 44458 cross to the left of the fence and continue on the same line through the crags.

The actual line of Sarn Helen goes straight along the track past Carreg y Fran, over a stile and into the forest. The path through the trees is boggy even in fine weather, and we found it was heavily overgrown as well. The moorland to the left of the track is also treacherously boggy.

There are two alternatives. You can bear left immediately past Carreg y Fran and pick your way round to the track up to Manod Quarry. Alternatively, climb over the stile and pick your way round to the left inside the forest edge. Climb the steep slope to the western corner of the forest. Here a track leaves the forest to join the road to Manod Quarry.

At SH 73420 45660 turn right off this track. At SH 73555 45968 turn left on the ‘Miners’ Road’, in fact the line of the Rhiw-bach Tramway (lots of photographs and information at, now a stony track leading north through the disused slate quarries.

The slate in Blaenau Ffestiniog is underground and must be mined rather than quarried. Here on the hills, instead of underground mines, there are huge pits which have been carved in the ground for access to the slate. These open beneath your feet with little or no warning: this is not an area to explore in poor visibility.

When the first of these pits opens in front of you, do not take the stony track to your left but keep on the grassy track to the right, though the two eventually rejoin. Follow the Miners’ Road around the contour.

At SH 73170 46728 turn right and walk past the extensive ruins of the Cwt-y-bugail quarry. Once past the buildings, bear left. A levelled slate track goes up over the spoil tips to the right of the huge quarry pit then bears slightly east of north to pick up the line of Sarn Helen again. At the top, look back down to the south towards the forest which we had to bypass. The tall chimney of Rhiw-bach Quarry marks the line of Sarn Helen on its way to the impenetrable woods.

There is no clear path from this point. Head north for the forest edge then turn right and look out for a stile to your left at SH 73170 46728 and a clear path down through the trees. The path is steep but well surfaced with slaty shale and easy to follow. Below you is Cwm Penamnen, a great misty bowl of green, ridged with trees. Cut down across a series of forest roads to the bottom.

At SH 73660 49000 is another cross-roads. Go straight on: you are now bearing left towards the valley bottom. Above and to your left the Afon Maesgwm plunges over a hundred feet down the cliffs.

The Maesgwm and the Penamnen join with a third stream at the bottom of the valley. Go over the bridge and past Ty’n-y-cwm Farm, and walk along the road to Dolwyddelan.

About a mile after Ty’n-y-cwm Farm and opposite the crags of Carreg Alltrem, there are some ruins to the left of the road. These are traditionally said to be the home of Meredydd ab Ieuan ap Robert, ancestor of the great Wynn clan of Gwydir. The church which Meredydd built is on the road from the station to the centre of the village. It is usually open during the day and well worth a visit.



Trawsfynydd to Dolwyddelan

Places to visit along this route


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