Lower Clydach Falls

SWC Walk 371 The Clydach Gorge (Brynmawr to Abergavenny or vice versa)

05-Aug-20 • thomasgrabow on Flickr

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Clydach Ironworks

SWC Walk 371 The Clydach Gorge (Brynmawr to Abergavenny or vice versa)

05-Aug-20 • thomasgrabow on Flickr

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Ogof Clogwyn cave and waterfall, Clydach Gorge

SWC Walk 371 The Clydach Gorge (Brynmawr to Abergavenny or vice versa)

07-Sep-20 • thomasgrabow on Flickr

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Old mine discharge, having left photogenic orange deposits; Clydach Gorge

SWC Walk 371 The Clydach Gorge (Brynmawr to Abergavenny or vice versa)

07-Sep-20 • thomasgrabow on Flickr

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Bench with Views: Sugar Loaf from Llannelly Quarry

SWC Walk 371 The Clydach Gorge (Brynmawr to Abergavenny or vice versa)

07-Sep-20 • thomasgrabow on Flickr

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Blorenge, above Cadfor Farmhouse

SWC Walk 371 The Clydach Gorge (Brynmawr to Abergavenny or vice versa)

05-Aug-20 • thomasgrabow on Flickr

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Lower Clydach Falls

SWC Walk 371 The Clydach Gorge (Brynmawr to Abergavenny or vice versa)

05-Aug-20 • thomasgrabow on Flickr

swcwalks swcwalk371

The Clydach Gorge (Brynmawr to Abergavenny or vice versa) walk

Wild and dramatic Clydach Gorge: waterfalls, cascades, fast-flowing waters, ancient beechwoods as well as an ironworks' ruins and an elevated railway line

Start & Finish

Start: Brynmawr Bus Station or Abergavenny Station
Finish: Abergavenny Station or Brynmawr Bus Station


17.9 km (11.1 mi) or 18.0 km (11.2 mi). Cumulative ascent/descent: 368/644m or 656m/380m. For a shorter walk, see below Walk options.


3 out of 10 or 6 out of 10. Time: 4 ½ hours or 5 ¼ hours walking time.


Brynmawr Bus Station, map reference SO 191 116, is 11 km west southwest of Abergavenny, 213 km west northwest of Charing Cross, 351m above sea level and in Blaenau Gwent, Wales. It is linked to train stations by several lines: X1 from Cwmbran, X4 from Merthyr Tydfil and Abergavenny, X15 from Newport and the 3 from Abergavenny. All operate Mon-Sat only.

Abergavenny Station, map reference SO 305 136, is 30 km south east of Brecon, 202 km west northwest of Charing Cross, 75m above sea level and in Monmouthshire, Wales. It is served by the Welsh Marches Line (Newport – Hereford), connecting at Newport to Paddington, with mostly two trains per hour (total journey time from 135 mins).

Saturday Walkers’ Club: This walk is doable as a daywalk from London. Take a train no later than 09.45.


OS Landranger Map: 161 (The Black Mountains)
OS Explorer Map: OL 13 (Brecon Beacons NP East)

Walk Notes

The Clydach, a short and fast river on the boundary of the Brecon Beacons National Park, flows off the southern slopes of the Mynydd Llangatwg through a wooded valley to the Usk River. For about 3 km the valley forms the Clydach Gorge/Cwm Clydach, containing waterfalls, cascades, fast-flowing waters and a few caves as well as some ancient beechwoods. The gorge is not only little-visited, but – despite the presence of the A465 Heads of the Valleys dual-carriageway, which also travels along the valley – also wild, dramatic and unspoilt.
The valley was a centre of early industry and remnants of limestone quarries, mines, an ironworks and several tramroad inclines are either passed or walked along, while a dismantled railway line provides an airy high-level walk route in the upper valley.
The steepness of the terrain and the narrow rock walls prevent a continuous path along the gorge, but three out-and-backs along good paths into the gorge, to waterfalls or caves, are described.
In the Lower Clydach Valley, you follow the rushing river closely through woods, then leave the Clydach to follow the Monmouthshire & Brecon Canal for a while, before heading to Abergavenny through lush pastures with views across the Usk Valley to the Black Mountains.

The walk is written up in both directions, down or up the valley, and bus stops nearby enable shorter walks.

Walk options

A start/finish at Abergavenny Bus Station cuts 750m distance, and 30m ascent – if at the end of the walk.

The three out-and-back routes into the Clydach Gorge can be omitted, they are (from west to east):
· Upper Clydach Falls and Ogof Clogwyn, 580m distance, 40m ascent;
· Devil’s Bridge and Pwll-y-Cwn, 540m distance, 70m ascent;
· Lower Clydach Falls, from 600m to 960m distance, negligible ascent.

Bus Lines 3 (Abergavenny – Brynmawr, Mon-Sat, 3 buses a day) and X4 (Merthyr Tydfil Abergavenny, Mon-Sat, hourly) travel along the Clydach Valley, calling on the A465 outside Clydach, in Clydach (not the X4), Gilwern and Govilon, enabling shorter versions of the route. Check the route map for the locations of the bus stops and make your way onto the route to join the text at the respective asterisks.




Abergavenny Ending
The Beaufort Arms 22 Main Road, Gilwern, Abergavenny, NP7 0AR (01873 832 235). The Beaufort is located 180m off route, 7.8 km from the end of the walk.
The Towpath Inn 49 Main Road, Gilwern, Abergavenny, NP7 0AU. The Towpath is located 7.6 km from the end of the walk and owned by Felinfoel Brewery.
Tafarn y Bont (formerly Bridgend Inn) Church Lane, Govilon, Abergavenny, NP7 9RP (01873 830 720). The Tafarn is located 5.4 km from the end of the walk.
The Lion Inn Govilon, Abergavenny, NP7 9RP. This pub is currently closed.
The Bridge Inn Merthyr Road, Llanfoist, Abergavenny, NP7 9LH (01873 854 831). The Bridge Inn is located 2.2 km from the end of the walk.
Plenty of places in Abergavenny’s Town Centre. See the walk directions for details.

Brynmawr Ending
The Hobby Horse 30 Greenland Rd, Brynmawr, Ebbw Vale NP23 4DT (01495 312 881).
The Gwesty 1 Clarence Street, Brynmawr, Ebbw Vale NP23 4AJ (01495 788 214).
The Talisman 9 Market Square, Brynmawr, Ebbw Vale NP23 4AJ (01495 312 138). Open all day every day.
Filling Station Café 17-18 Market Square, Brynmawr, Ebbw Vale NP23 4AJ (07572 981 903). Closed Sundays.


Brynmawr (meaning 'big hill') is a market town in Blaenau Gwent. The town, sometimes cited as the highest in Wales, is situated at the head of the South Wales Valleys. Prior to the Industrial Revolution a small village called Gwaun Helygen, it grew with the development of the coal mining and iron industries in the early 19th century and expanded into a prosperous town after the expansion of the Nantyglo, Clydach and Beaufort Ironworks meant housing was required for the workers.
Until the reorganisation of local authorities in 1974, Brynmawr was administered as part of Brecknockshire.

Clydach River, Clydach Gorge, Cwm Clydach National Nature Reserve
The River Clydach is a short, steep and fast-flowing river crossing from the county borough of Blaenau Gwent into Monmouthshire in the Brecon Beacons National Park and on the edge of the Blaenavon World Heritage Site. It is around 10 km in length. The river rises on the southern slopes of Mynydd Llangatwg, then heads southeast through Clydach Dingle past Brynmawr. It then enters the spectacular Clydach Gorge, dropping about 300m over 5.6 km to Gilwern and its confluence with the River Usk.
‘Clydach’ is a common name for watercourses in south Wales and is thought to derive from an old Welsh word for ‘swift’ or possibly ‘stony’, both of which would apply to the Clydach River.
The Gorge was one of the first locations in the region to be industrialised though it still retains its natural environment. It includes Smart's Bridge, an early cast iron bridge now Grade II*-listed, the remains of a late 18th century ironworks which are now a Scheduled Ancient Monument, as well as some limeworks.

Brecon Beacons National Park
Home to spectacular landscapes, a rich variety of wildlife and fascinating cultural and geological heritage, the Brecon Beacons National Park in Mid-Wales boasts a magnificent array of Old Red Sandstone peaks, open moorland and green valleys, spanning 1,344 km2 (520 mi2). Pen y Fan within the Central Beacons is perhaps the best-known summit but there are many others in the five distinct parts of the National Park (Black Mountain (Y Mynydd Du) in the far west, Fforest Fawr, Central Beacons, the Llangattock and Llangynidr Hills, and the Black Mountains to the east).

Merthyr, Tredegar and Abergavenny Railway
The M, T & A, also known as the Heads of the Valleysline, was a railway line operating between 1860 and 1958 between Abergavenny and Merthyr Tydfil. It purchased Bailey's Tramroad which ran from Nantyglo Ironworks to Govilon Wharf, and even before the first section was opened in 1862 it was leased by the LNWR who were seeking to capitalise on the expanding heavy industry in the region. Construction of this railway line was judged to be a significant engineering feat as it had to climb the Clydach Gorge and the gradient was such that special locomotives had to be designed. The railway closed in 1958 and is now a public footpath and cycleway.

Monmouthshire & Brecon Canal (The Mon & Brec)
The Monmouthshire & Brecon Canal/Camlas Sir Fynwy a Brycheiniog is a small network of canals following the line of the Usk Valley through the Brecon Beacons National Park. It is currently navigable for 56 km and with only 6 locks (5 of them in Llangynidr). Its rural character and tranquillity belie its original purpose as an industrial corridor for coal and iron, brought to the canal by a network of tramways and/or railroads.
The "Mon and Brec" was originally two independent canals – the Monmouthshire Canal from Newport to Pontymoile Basin and the Brecknock and Abergavenny Canal from Pontymoile to Brecon, before joining in 1812. Both canals were abandoned in 1962, but the Brecknock and Abergavenny route and a small section of the Monmouthshire route have been reopened since 1970. Much of the rest of the original Monmouthshire Canal is the subject of a restoration plan, which includes the construction of a marina at Newport.

Usk Valley Walk/Llwybr Dyffryn Wysg
The Usk Valley Walk is a linear 78 km (48 mi) waymarked Long-Distance Path starting in the south from Caerleon and following the Usk (and the Monmouthshire & Brecon Canal) upstream to Brecon.

Usk Valley/River Usk (Afon Wysg)
The River Usk (Afon Wysg in Welsh) rises on the northern slopes of The Black Mountain (Y Mynydd Du in Welsh), in the westernmost part of the Brecon Beacons National Park, initially forming the boundary between Carmarthenshire and Powys. It flows north into Usk Reservoir, then east by Sennybridge to Brecon before turning southeast to flow by Talybont-on-Usk, Crickhowell and Abergavenny after which it takes a more southerly course. Beyond the eponymous town of Usk it passes the Roman legionary fortress of Caerleon to flow through the heart of the city of Newport and into the Severn estuary at Uskmouth at Newport Wetlands. Its total length is 102 km/63 mi.
The name of the river derives from a Common Brittonic word meaning "abounding in fish" or "water", which also appears in other river names such as Exe, Axe, Esk and other variants.
The whole river downstream of Usk Reservoir has been designated a Site of Special Scientific Interest and has long been a noted salmon and trout fishing river.

Usk Bridge (or Abergavenny Bridge/Pont y Fenni)

The bridge crosses the River Usk at the boundary between Abergavenny and Llanfoist, carrying the A4143. It is probably of mid-15th century origin but was substantially reconstructed in the 19th century, to support a tramroad, and again when the two bridges were combined. The tramway, which originally ran parallel to the bridge, carried the horse-drawn Llanvihangel Railway from the Monmouth & Brecon canal at Llanfoist.
The bridge was the subject of two paintings by JMW Turner dating from the 1790s. The first, Abergavenny Bridge, Monmouthshire, Clearing Up after a Showery Day, is held in the collection of the V&A and the second (Abergavenny Bridge) by The Tate. It is a Grade II* listed building and a Scheduled Monument.

Abergavenny/Y Fenni, Abergavenny Castle/Castell y Fenni
Abergavenny (Welsh: Y Fenni, archaically Abergafenni meaning "Mouth of the River Gavenny") is a market town in Monmouthshire, Wales, about 10 km from the border with England. It is located at the confluence of the River Usk and a tributary stream, the Gavenny and on the A40 trunk road and the A465 Heads of the Valleys road and is promoted as a Gateway to Wales.
Originally it was the site of a Roman fort, Gobannium (after Gobannia, Brythonic for "river of the blacksmiths").
Abergavenny is almost entirely surrounded by mountains and hills: the Blorenge, the Sugar Loaf, The Skirrid/Ysgyryd Fawr and Fach, Deri, Rholben and Mynydd Llanwenarth, with Sugar Loaf being the highest.
During September the town holds the Abergavenny Food Festival.

Abergavenny Castle (Welsh: Castell y Fenni) is a ruined castle, established by the Norman lord Hamelin de Balun ca. 1087 to overlook the River Usk and its valley, and so guard against incursions into the lowland areas south and east of the town by the Welsh from the hills to the north and west. It was the site of a massacre of Welsh noblemen in 1175, and was attacked during the early 15th century Glyndŵr Rising. The high, formidable curtain wall, dating from the 12th century, is now the most impressive part of the ruin. A lodge was built on the top of the motte in the 19th century and now houses the town’s Museum (open daily with free admission).

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By Train

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Start Brynmawr bus station, Ebbw Vale, Wales, NP23 4XG Map Directions

Finish NP7 5HS Map Directions


National Rail: 03457 48 49 50 • Travelline (bus times): 0871 200 22 33 (12p/min) • TFL (London) : 0343 222 1234


Oct-20 Thomas G

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Walk Directions  

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This is just the introduction. This walk's detailed directions are in a PDF available from wwww.walkingclub.org.uk