The Black Mountain (Y Mynydd Du) from Glyntawe walk

8 out of 10, with 6 ½ hours walking time.

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 join the main walk’s valley return route: 15.6 km/9.7 mi with 720m ascent, rated 7/10.
• 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 7/10. [!] 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.

OS Explorer: OL12 (Brecon Beacons National Park)
OS Landranger: 160 (Brecon Beacons)
Harvey Superwalker XT25: Breacon Beacons West/Bannau Brycheiniog Gorllewin
Harvey British Mountain Map: Breacon Beacons/Bannau Brycheiniog

Glyntawe (Tawe Bridge) Bus Stop, map reference SN 846 167, is 248 km west of Charing Cross, 208m above sea level and in the Tawe (or Swansea) Valley (Cwm Tawe in Welsh) in Powys, Wales. It is on line T6 (Swansea - Neath - Ystradgynlais – Brecon), with up to 11 buses a day Mon-Sat and 5 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.

Saturday Walker's Club: This walk is doable as a daywalk from London if you have motorised transport.

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.