Trail Running > Routes > Brecon Beacons Routes > Allt yr Esgair & Llangorse Lake
A scenic 13 km trail run linking Allt yr Esgair and Llangorse Lake, with wooded slopes, open ridges and panoramic views.
Why run this trail?
At just 393 m, Allt yr Esgair – known locally as “The Allt” – is dwarfed by many of its neighbouring peaks. Yet its isolated position offers a superb bird’s-eye view over the Usk Valley and beyond.
Despite its modest height, The Allt packs an impressive range of features into its steep, wooded slopes: a Roman road, a Bronze Age burial mound, the remains of an Iron Age hill fort, and a craggy sandstone escarpment that delivers panoramic views across the Central Beacons and the Black Mountains.
This route also takes in Llangorse Lake, the largest natural body of water in South Wales. While there’s no public right of way around its entire perimeter, it’s well worth skirting what you can and seeking out the crannog – a reconstruction of a 10th-century royal dwelling, raised on stilts among the reeds.
The low-lying fields around the lake flood regularly through winter, forming a rich wetland habitat for birdlife. As a result, this route is best tackled after a prolonged spell of dry weather in spring or summer – unless you fancy running across what feels suspiciously like a recently drained lake bed (as I discovered to my dismay in late April). Fields that are flooded enough for swans to swim on rarely make for ideal running conditions!
The route can also be run in reverse, starting from the lakeside car park near the village of Llangorse. With a café, bar and the occasional ice cream van nearby, it makes for a civilised finish to a morning on the hills.
A40 Lay-by to Allt yr Esgair
Setting out from the parking and picnic area just off the A40, follow the fingerpost up the metalled lane towards the farm and campsite. After 40 m, turn left through a metal gate. The track climbs gently across meadows and gorse to enter woodland after around 350 m.
The woodland trail provides a perfectly pitched warm-up on a well-packed surface, with views opening across the Usk Valley through the trees on your left.
The path eventually meets a gravel lane – continue straight across, signposted Pennorth. The trail soon narrows again through woodland before emerging onto a steep, sloping field on the lower flanks of The Allt. Follow the obvious grassy track across the hillside and the western tip of Llangorse Lake soon comes into view.
Allt yr Esgair to Llangorse Lake
The trail begins to descend – passing a covered reservoir on your left – before reaching a junction of paths. Turn left into an old hollow way through the trees and follow this stony track downhill for around 500 m, passing Llangasty Village Hall to emerge onto a lane.
Turn right, then immediately left towards Tŷ-Mawr Farm. Just before reaching the farmhouse, turn right onto a gravel track. After 150 m, follow the footpath into a large paddock and continue towards the treeline in the far-left corner. Turn left through a gate onto a grassy footpath that skirts the shoreline (though set back from it by around 100 m).
Continue across several fields as the path curves clockwise around the lake. The shoreline is dotted with striking trees that look as though they belong in a Louisiana delta.
This entire section is prone to flooding in winter – look out for the debris and driftwood marking previous high water levels as the sailing club comes into view.
Note: On my visit in late April, the final field before the main lakeside area was impassable due to deep flooding (approx. SO 12399 27074). I was forced to re-route, skirting waterlogged ground before crossing the small wooden bridge over the Afon Llynfi onto Llangors Common.
From here, head down to the shoreline for superb views of Mynydd Llangorse and Mynydd Troed, with The Allt rising behind you. A wander onto the jetties reveals striking views of Pen y Fan and the Central Beacons, forming a dramatic backdrop to the crannog – perched evocatively on wooden piles among the reeds.
The lake itself has something of a fenland feel to it, framed by tall reeds teeming with birdlife, and punctuated by the occasional quiet passage of a sailing boat.
Llangorse Lake to Llangasty Village Hall
Retrace your steps across the common and re-cross the wooden bridge, keeping the hedgerow and drainage dyke to your right. Follow the line of the hedge across several fields, crossing a stream (now on your right) as the path becomes more defined.
Keep left where the track splits, crossing the stream again before heading south along the edges of some small arable fields. Allt yr Esgair reappears ahead, offering a useful navigational reference.
You’ll emerge onto a metalled farm track – look for the footpath sign opposite and turn left. After 100 m, turn right into a field and take the right-hand track heading south. After 300 m, you’ll rejoin the lakeside pastures.
Passing through a line of trees, bear right as the track splits away from the lake. Continue through an orchard to reach a farm track west of Tŷ-Mawr Farm, then turn left and retrace your steps back to Llangasty Village Hall.
Llangasty Village Hall to Allt yr Esgair
Pass the hall on your right and begin climbing back up the hollow way you descended earlier. At the junction of paths, continue straight on to start the climb up to The Allt.
The track splits a couple of times and can be easy to misread: bear right at the first split, then left shortly after. The outer paths bypass the ridge entirely – not what you want here.
Climb steadily for around 400 m through scattered trees and gorse to reach more open ground where paths converge. Continue uphill, keeping the dry stone wall on your left, until you reach the summit.
There’s no trig point or cairn at the top, but the views more than compensate: east to the lake and Black Mountains, and west across the Central Beacons and the Usk Valley. The rocky escarpment on the western side is the perfect spot to pause and take it all in – an outstanding panorama for such a modest summit.
Allt yr Esgair to A40
From the summit, the path descends quickly through farmland, with some stony sections underfoot. Where the track splits, bear right and continue descending south-west as the route curves around the back of the campsite and farm.
Rejoin the metalled lane near the farmhouse and follow it downhill for the final 250 m back to the A40 lay-by.
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Disclaimer
All routes and GPX files are provided as a guide only. Conditions, rights of way, and landmarks may change. Always carry an up‑to‑date map and use your own judgement. See the Trail Run Disclaimer page for details.