Saturday Walkers Club

The Black Mountain (Y Mynydd Du) from Glyntawe Walk

A spectacular ridge walk to Fan Brycheiniog, Fan Foel and Waun Lefrith. Return via a glacial valley below the ridge, or remote moorland, shakeholes and a waterfall.


This walk has several options for experienced mountain walkers. There is also an Easy Version

Length 21.9 km (13.7 mi), of which 200m are on tarmac or concrete. Cumulative ascent/descent: 1000m. For a shorter walk, an alternative start point and an alternative return route, see below Walk options.

10 out of 10 Time: 7 hours walking time.


Glyntawe (Tawe Bridge) Bus Stop is on line T6 (Swansea - Neath - Ystradgynlais – Brecon), with up to 8 buses a day Mon-Sat and 4 on Sundays and Bank Holidays, with a journey time of 45 mins from Neath (and 30 mins from Brecon). The journey time by train from London to Neath is from 2 ¾ hours.

Stay Saturday Walkers’ Club: This walk is not doable as a daywalk from London. Accommodation is available in Glyntawe, nearby in Craig-Y-Nos or Pen-Y-Cae, and along the bus line in Ystradgynlais, Sennybridge or Brecon.
OS Map

OS Landranger Map: 160 (Brecon Beacons) OS Explorer Map: OL12 (Brecon Beacons National Park)

Walk Notes

The Black Mountain (Y Mynydd Du in Welsh), in the Western Brecon Beacons, is often referred to as the last wilderness in the Brecon Beacons National Park and a walk along it as South Britain’s best ridge walk. It traverses a series of high peaks along a sequence of steep dramatic escarpments and features some of the most spectacular upland scenery in Britain. The route involves remote and rugged terrain, with a couple of glacial lakes and superb mountain views and leads almost entirely through open country.

From the Tawe Valley you rise steeply up a grassy hillside onto the first ridge, Fan Hir, and soon follow its edge with some far views to the two famous peaks in the Central Beacons: Pen y Fan and Corn Du. After dropping into a saddle you re-ascend to Fan Brycheiniog and then onto the northerly top Fan Foel. The views of the moorland and open country to the north are spectacular, and reveal the isolation of the range.

Turn west through a deep saddle to conquer the even more spectacular ridge of Bannau Sir Gaer.

The return route along the bottom of the steep escarpments, past some glacial lakes and moraines, reveals a different and fascinating perspective of the high buttresses and some steeply carved valleys below.

Shorter circular or out-and-back options, as well as a start from near the northerly end, are described. An alternative return route from the last top initially leads through open pathless, sometimes boggy, moorland, then through a veritable moonscape of shake holes, swallow holes, pot holes and limestone pavement before dropping back into the Tawe Valley (Cwm Tawe in Welsh).

Note: The Black Mountains (plural) are a range of hills in the Eastern Brecon Beacons.


Variations on the main route

  • A Short Circular Walk: cut out the last part of the ridge (Bannau Sir Gaer) by descending the flank of the northerly peak Fan Foel to return with the main walk route: 15.6 km/9.7 mi with 720m ascent, rated 8/10.
  • An out-and-back steeply onto the ridge then to any of the peaks: from 10.9 km/6.8 mi.
  • An out-and-back steeply onto the ridge then to any of the peaks, but descending from the Bwlch Giedd (saddle) onto the main walk’s valley return route: from 12.0 km/7.5 mi.
  • An Alternative Ascent Route, recommended in wet and/or windy conditions: walk along the foot of the Fan Hir escarpment and then late onto the ridge at the Bwlch Giedd (saddle), this cuts 110m ascent. (i.e. out and back along the bottom of the ridge, with a final ascent to the top)

Blaenau Circular

  • An Alternative Start from the north (motorised transport needed): this adds 1.0 km/0.6 mi distance and 94m ascent, but the pubs in Glyntawe become possible lunch stops, ca. 10.0 km/6.3 mi into the walk. You can also combine this start with one of the alternative ascents to the ridge for a short or medium circular walk (picnic lunch only though). For details see the write-up.

Return via the Swallow Holes

  • An Alternative Return Route leads on a westerly loop from the last top on Waun Lefrith via an area of Shake Holes and Swallow Holes to Glyntawe, total length: 20.6 km/12.8 mi with 760m ascent, rating 9/10. [!] This includes several kilometres of pathless walking through a grassy boggy hillside and requires good map-and-compass skills or a reliable GPS-led device, and is not recommended in poor visibility. [!] A Diversion to the beautiful Sgwd Ddu (Black Waterfall) on the Afon Haffes (the Haffes River) adds 0.6 km and 42m ascent to this route.
Lunch and Tea

The two pubs in Glyntawe come at the end of the walk, but could be lunch stops if starting from the Blaenau car park:

Tafarn y Garreg A 4067, Glyntawe, Swansea, Powys, SA9 1GS (01639 731 415). The Tafarn y Garreg had been shut for several years but re-opened in summer 2015. Open 12.00-23.00 Tue-Fri, 12.00-23.00 Sat and 12.00-18.00 Sun. Food served 12.00-20.00 Tue-Fri and 12.00-21.00 Sat-Sun.
The Gwyn Arms A 4067, Glyntawe, Swansea, Powys, SA9 1GP (01639 730 310). A roadside pub in a picturesque valley with a large garden, offering good value pub food every day. Open 11.00-late daily. Food served 12.00-20.00 Mon-Sat and 12.00-16.00 Sun.

Brecon Beacons

The Brecon Beacons is a national park in south Wales. It consists of bare, grassy, glacial mountains, with north facing escarpments. Its peaks, just shy of 1,000m (3,000ft), are the highest mountains in the southern UK. The national park is also noted for reservoirs, and the Dan yr Ogof caves. Its 4 mountain areas, from west to east are:

The Black Mountain (singular!).

Fan Brycheiniog (803m) and the Dan yr Ogof caves.

medium The Black Mountain (Fan Brycheiniog and Fan Foel) from Glyntawe - The best ridge walk in the southern UK to a summit.
tough The Black Mountain (Y Mynydd Du) from Glyntawe - A longer version of the above

Fforest Fawr.

Fan Gyhirych (725m), Fan Nedd (663m), Fan Fawr (734m), and the Henrhyd waterfalls (Sgwd Henrhyd)

low-level Henrhyd Falls (Sgwd Henrhyd) from Craig y Nos - Famous waterfall

The Brecon Beacons.

Pen y Fan (886m), Corn Du (873m), Cribyn (795m), Fan y Big (719m), Waun Rydd (769m). South of Brecon, north of Merthyr Tydfil.

medium Brecon Beacons (Pen Y Fan) from Storey Arms - Short walk to the highest summit in southern England
tough Brecon Beacons (Pen Y Fan) Horseshoe from Neuadd Reservoir - Classic walk bagging all the Brecon peaks

The Black Mountains (plural!).

Waun Fach (811m), Black Mountain (703m). Abergavenny to the south. Hay-on-Wye to the north. On our 'to do' list


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By Car

Start: Glyntawe, Penycae, Swansea, West Glamorgan, SA9 1GS | Directions



Start walking Large print Using GPS data

National Rail: 03457 48 49 50 • Travelline SE (bus times): 0871 200 2233 (12p/min) • TFL (London) : 0343 222 1234



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Walk Directions  

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