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Mynydd y Llan & source of the Usk

Brecon Beacons/Bannau Brycheiniog Walk

Nat Park - Brecon Beacons - Brecon Beacons West

County/Area - Carmarthenshire

Author - Lou Johnson

Length - 6.7 miles / 10.9 km    Ascent - 800 feet / 242 metres

Time - 4 hours 10 minutes    Grade - easy/mod

Maps Ordnance Survey Logo Anquet Maps Logo

Ordnance Survey Explorer OL12Sheet Map1:25kBUY
Anquet OS Explorer OL12Digital Map1:25kBUY

Walk Route Description

Photo from the walk - Mynydd y Llan & source of the Usk
Click image to see photo description.

This circular walk in the Brecon Beacons National Park covers an area of wild moorland north of Llanddeusant. The route starts from Pont'ar Wysg and crosses the moor before descending into a valley of fertile farmland. The walk continues to cross the flank of Mynydd y Llan (423 m) with views south to the Black Mountains including the summit of Picws Du. Veering north the route crosses moorland which is the source of the River Usk to return to the start. The relevant Ordnance Survey 1:25k map is useful for the final section of the walk.

The route starts from the car park on the Powys side of Pont'ar Wysg (grid ref. SN820271). After parking cross the bridge into Carmarthenshire and follow the lane across the moor. Continue for three kilometres to cross a cattlegrid. Continue for a further 400 metres and turn left down a track with adjacent fingerpost (grid ref. SN 787263). Continue down past Blaenllechach Farm (on your right) to a footbridge over the Afon LLechach. A clear track crosses a field with hedge on your right to reach some derelict building where you turn right to follow the continuing track. Stay on the track for 800 metres to reach a stream with woodland on your left and a footpath sign (grid ref. SN784252).

Turn left uphill and continue to reach open access land (grid ref. SN786252). Careful navigation is required from this point. Continue ahead uphill onto Mynydd y Llan. As you make progress up the slope there are excellent views across wild country to the imposing Carmarthen Fans including Picws Du and the steep escarpment. The path keeps the summit of Mynydd y Llan on your left and maintains direction roughly to the east. Two kilometres from entering the moor, the path approaches the steep sided valley containing Nant y Cregiau. Reaching a path junction (grid ref. SN804247, continue ahead with Bryn Mawr rising to your left.

Continue up and across a shallow col and start to descend. There is no clear path across the open moorland. Initially the route heads northeast and after 600 metres veer half left and walk parallel to the infant River Usk which is on your right. In clear weather the route back to the start fords two side streams before reaching Pont'ar Wysg. Turn right across the bridge and return to the car park.

Other walks nearby

Walk 3559 Picws Du & Llyn y Fan Fach from near Llanddeusantmoderate5.3 miles
Walk 1672 Llyn-y-Fan-Fawr & Mynydd Ddu from Llanddeusant mod/hard12.0 miles
Walk 3555 Carreg yr Ogof & Bannau Sir Gaer from Llanddeusantmoderate6.7 miles
Walk 3563 Fan Brycheiniog and Picws Dumoderate7.1 miles
Walk 2645 Fan Gyhirych & Fan Bwlch Chwyth, Fforest Fawrmoderate8.0 miles
Walk 2646 Fan Nedd & Fan Bwlch Chwyth, Fforest Fawrmoderate7.0 miles
Walk 2647 Fan Gyhirych, Fan Nedd & Fan Bwlch Chwythmoderate10.0 miles
Walk 2643 Fan Frynych & Fan Llia, Fforest Fawrmoderate8.0 miles
Walk 2641 Fan Fawr & Fan Frynych, Fforest Fawrmoderate6.5 miles
Walk 2648 The Black Mountain, Brecon Beaconsmoderate8.0 miles

Recommended Books & eBooks

Walking on the Brecon Beacons

Walking on the Brecon Beacons45 circular day walks are described in this guidebook to the Brecon Beacons National Park. From west to east, Mynydd Du, Fforest Fawr, the Brecon Beacons and the Black Mountains these mountain and valley routes offer many options, highlighting the natural features. The walks described explore dramatic waterfalls, wooded gorges and upland valleys.
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Walking in Carmarthenshire

Walking in CarmarthenshireGuidebook to 30 walking routes (2 to 10 miles) in Carmarthenshire, south Wales, including sections of Carmarthenshire Coast Path. Walks for all abilities, including coastal, river, forest and hill walks in Cambrian Mountains, Tywi Valley, Y Mynydd Du (Black Mountains) and Brecon Beacons. Easy access from Bristol, Cardiff and Swansea.
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