Best Places to Visit in Rhondda Cynon Taf & the Valleys
Written by UK Hidden Gems Editorial
Updated 5 August 2026
The best places to visit in Rhondda Cynon Taf & the Valleys are Llyn Cwm Llwch, Porth Yr Ogof Caves, Upper Neuadd Reservoir, Sgwd Isaf Clun-gwyn, Pontsarn Blue Pool, Lower Neuadd Reservoir, Lower Cilhepste Falls and Pistyll Goleu.
Rhondda Cynon Taf and the valleys reach up from the coalfield towns into the southern edge of the Bannau Brycheiniog, the Brecon Beacons, where the rivers carve waterfall country and old reservoirs sit below the peaks. The Waterfall Country near Ystradfellte offers the walk-behind curtain of Sgwd yr Eira, the staggered cascades of Sgwd Isaf Clun-gwyn on the Mellte, and the wide dark cave mouth of Porth yr Ogof, where the river vanishes underground.
Higher up, below Pen y Fan, the glacial Llyn Cwm Llwch sits in its hollow and the drained Upper and Lower Neuadd reservoirs keep their old dams in the central Beacons. For a swim there is the Pontsarn blue pool below its viaduct near Merthyr, and deeper in the coalfield hills the quiet Pistyll Goleu drops in St Gwynno's Forest.
Some are grand set pieces, others quiet corners. Here are eight places to visit across Rhondda Cynon Taf and the valleys.
Llyn Cwm Llwch
Photo: Alan Richards via Geograph.org.uk
Llyn Cwm Llwch is a small glacial lake in a rock hollow directly below Pen y Fan and Corn Du, the highest peaks of the Brecon Beacons. A curved bank of moraine, left by the ice, rims its lower edge.
A well-used path climbs to it from the Cwm Llwch car park to the north, passing an obelisk that marks the spot where a five-year-old boy, Tommy Jones, died on the hills in 1900. The lake carries an old tale of a hidden fairy island.
Its outflow runs down to join the River Usk at Brecon.
Porth Yr Ogof Caves
Photo: Gordon Hatton via Geograph.org.uk
Porth yr Ogof is a large cave near Ystradfellte in the Waterfall Country of the Brecon Beacons, where the River Mellte disappears underground into what is said to be the widest cave entrance in Wales, around twenty metres across. From a car park nearby, visitors walk down to the great dark mouth of the cave, where casual visitors look in or step onto a dry ledge, while the passages deeper inside, running for over two kilometres, are for experienced and guided cavers only.
Downstream the water rises again at a pool. The river and pools here have a history of drownings, so the deeper water is treated with respect.
Upper Neuadd Reservoir
Photo: Sharon Loxton via Geograph.org.uk
Upper Neuadd Reservoir lies at the head of the Taf Fechan valley below Pen y Fan, in the Bannau Brycheiniog, or Brecon Beacons. Its masonry dam was built between 1896 and 1902, but the reservoir behind it was drained around 2015 for dam-safety reasons, so visitors now see a grassy, silted basin with the old dam and its gothic spillway tower still standing.
The dam is a listed structure. A layby gives way to foot and bike access, and the site links into the popular round of the Pen y Fan horseshoe.
Sgwd Isaf Clun-gwyn
Photo: Gareth James via Geograph.org.uk
Sgwd Isaf Clun-gwyn, the lower fall of the white meadow, is a waterfall on the Afon Mellte in the Waterfall Country of the Brecon Beacons, near Ystradfellte. It is the most complex of the falls on this river, a staggered run of several cascades and ledges rather than a single drop, so it is hard to see the whole of it from any one spot.
It lies on the Four Waterfalls Walk from the Cwm Porth car park, on a route that involves steep and scrambly descents to the riverbank. It sits between the upper Clun-gwyn fall and Sgwd y Pannwr.
Pontsarn Blue Pool
Photo: Alan Bowring via Geograph.org.uk
Pontsarn Blue Pool, known in Welsh as Pwll Glas, is a large natural swimming hole on the Taf Fechan river in a wooded gorge north of Merthyr Tydfil, in the Brecon Beacons. The clear water deepens quickly and is mostly free of submerged rock, with cascades and channels running through it, and it lies right below the arches of the old Pontsarn railway viaduct beside the Taff Trail.
A short scramble down rocky ledges from the bridge reaches the water, with a second pool a little way upstream. It is cold, and unsafe when the river runs high after rain.
Lower Neuadd Reservoir
Photo: CHARLES GORDON CLARK via Geograph.org.uk
Lower Neuadd Reservoir sits in the Taf Fechan valley below the southern side of Pen y Fan and Corn Du, in the Brecon Beacons. Built in 1884, it has since been taken out of use: the dam was notched and the water drained, so the river now runs naturally through the old basin, crossed by a new footbridge.
What remains is the modified dam, an eight-sided valve house, the old spillway and the shell of a burnt-out control building, with grass grown back over much of the ground. It is a common starting point for the walk around the Pen y Fan horseshoe.
Lower Cilhepste Falls
Photo: Nick Earl via Geograph.org.uk
Lower Cilhepste Falls is a local name for Sgwd yr Eira, one of the best-known waterfalls in the Waterfall Country of the Vale of Neath, in the Brecon Beacons. The Afon Hepste pours over a broad ledge of rock, and the great thing about this fall is that a path runs along the ledge behind the curtain of water, so you can walk right behind it.
It is reached on a walk of about four miles from the Craig y Ddinas car park, or taken in on the longer Four Waterfalls Walk. Steps drop steeply down to the fall, and the ledge behind is wet and slippery.
Pistyll Goleu
Photo: Alan Bowring via Geograph.org.uk
Pistyll Goleu Ten minutes on foot from the roadside is all it takes to reach this modest, photogenic fall, where the Sychnant stream slides over a face of Pennant sandstone in St Gwynno's Forest near Llanwonno. It hides away in the hills of Rhondda Cynon Taf, little known and easy to miss, and many walkers fold it into a longer round of the Llanwonno waterfalls.
Photographers love the mossy, green-shaded setting, which comes alive after rain. There are no facilities out here, so bring what you need, but for so little effort the reward is a genuinely lovely spot.
FAQs
Which waterfall in Rhondda Cynon Taf and the valleys can you walk behind?
Sgwd yr Eira, known locally as Lower Cilhepste Falls, on the Afon Hepste in the Waterfall Country, has a path running along a ledge behind the curtain of water, so you can walk right behind the fall. It is reached on a walk of about four miles from the Craig y Ddinas car park, with steep steps down and a wet, slippery ledge.
Where can you swim safely in Rhondda Cynon Taf and the valleys?
The Pontsarn blue pool on the Taf Fechan north of Merthyr is a large natural swimming hole with clear water that deepens quickly and is mostly free of submerged rock, reached on a short scramble below the old viaduct. It is cold, and unsafe when the river runs high after rain, so settled weather is best.
What are the Neuadd reservoirs near Pen y Fan like now?
Both Neuadd reservoirs have been taken out of use. Upper Neuadd was drained around 2015, leaving a grassy basin with its old dam and gothic spillway tower, while Lower Neuadd was notched and drained so the river runs through the old basin. Both sit below Pen y Fan and are common starts for the Pen y Fan horseshoe walk.
Conclusion
Rhondda Cynon Taf and the valleys reach up from the coalfield towns into the southern Bannau Brycheiniog. The Waterfall Country near Ystradfellte offers the walk-behind curtain of Sgwd yr Eira, the staggered cascades of Sgwd Isaf Clun-gwyn, and the wide dark mouth of Porth yr Ogof, where the Mellte vanishes underground.
Higher up, below Pen y Fan, the glacial Llyn Cwm Llwch sits in its hollow and the drained Upper and Lower Neuadd reservoirs keep their old dams. For a swim there is the Pontsarn blue pool below its viaduct near Merthyr, and deeper in the hills the quiet Pistyll Goleu drops in St Gwynno's Forest.
From walk-behind fall to hill reservoir, these are the places to seek out across Rhondda Cynon Taf and the valleys.
