Ogof Ffynnon Ddu Nature Reserve (NRW)

Book Tickets Online


The grassy uplands opposite Craig-y-Nos Country Park and the Dan-yr-Ogof National Showcaves Centre hide a labyrinth network of caverns and cascades, stalgamites and stalactites, passageways and potholes.

Ogof Ffynnon Ddu means Cave of the Black Spring, a reference to the vast cave system discovered beneath the moors in 1946. It’s a 300m deep underground world with an overall length of over 30 miles and the difference in level between its highest and lowest points is 308m, a record for the UK. Access to the caves is confined to experienced cavers only.

The Reserve, situated at over 350m above sea level, is one of Wales’ most exhilarating National Nature Reserves, with breathtaking views across South Wales and the Brecon Beacons. The terrain is a mixture of rocky outcrops and tufty moorland, with few obvious paths.

Herb-rich grasslands grow on the limestone, while heather and bilberry moorland covers the acid peat lying on the millstone grit. The flowers are at their best in early summer; the reserve contains rarities, including mountain everlasting, autumn gentian, mossy saxifrage and great burnet. Hairy greenweed, a low, yellow-flowering shrub, is one particularly rare species growing here.

Birds on the reserve include peregrine falcons, nightjars, ravens, ring ouzels, wheatears, red grouse and red kites. Below ground, the waters contain crustaceans that can only survive underground, and the cave is a winter habitat for moths and bats.

For a gentle, easy walk you can follow the old railway line along the side of the valley. Although this just skirts the edge of the reserve, the views are splendid. More experienced and enthusiastic walkers can access the heart of the Reserve by following paths upwards from the car park. One particularly well-defined and convenient pathway is the old tramway, a steep incline that climbs to the reserve’s eastern boundary.

Book Tickets



  • Free Parking

Map & Directions

Road Directions

Ogof Ffynnon Ddu National Nature Reserve is six miles north of Ystradgynlais.

By Car: Take the A4067 from Ystradgynlais to Abercraf and Pen y Cae. Continue through Pen y Cae and turn right down a minor road signposted to Penwyllt. Follow brown and white tourist signs over river and left at T-junction. Go past disused quarry along track to car park.

Ogof Ffynnon Ddu National Nature Reserve is on Ordnance Survey (OS) map OL 12. The OS grid reference is SN 856 155.

Accessible by Public Transport: Neath station is 22 miles away.

Ogof Ffynnon Ddu Nature Reserve (NRW)

Type:Nature Reserve

Ystradgynlais, Brecon Beacons National Park, SA9 1GQ

Add Ogof Ffynnon Ddu Nature Reserve (NRW) to your Itinerary

Close window

Call direct on:

Tel0300 0653000

What's Nearby

  1. Craig-y-nos Country Park is on the southern edge of the Brecon Beacons National Park. It…

    0.77 miles away
  2. The Castle overlooks Craig-y-Nos Country Park, in the Brecon Beacons National Park, an…

    1.06 miles away
  3. Wales' best kept secret for 315 million years! The National Showcaves Centre for Wales…

    2.93 miles away
  4. Penderyn Distillery is located in the former Old Board School in Lloyd St, Llandudno. You…

    7.32 miles away
  1. Craig Cerrig-gleisiad and Fan Frynych National Nature Reserve is a 156 acre (631,000 m²)…

    7.72 miles away
  2. Pen y Fan and Corn Du are the two highest peaks of the central Brecon Beacons. They…

    8.09 miles away
  3. The Usk Reservoir is a remote upland 280 acre reservoir surrounded by the Glasfynnedd…

    8.29 miles away
  4. Bannau Brycheiniog | Brecon Beacons National Park lies on the border between Mid Wales…

    10.04 miles away
  5. The Bannau Brycheiniog Visitor Centre provides information and interpretation for…

    10.04 miles away
  6. Gnoll Estate Country Park

    The Gnoll Estate Country Park offers visitors the delights of an eighteenth century…

    11.82 miles away
  7. Dare Valley Country Park

    The Dare Valley is a beautiful glacial valley. It includes all of the classic features of…

    11.86 miles away
  8. St John the Baptist Church, Aberdare

    St John's Church was built in the latter part of the 12th Century, as a Chapel of Ease…

    11.93 miles away
  9. There are few castles in Wales - or Europe for that matter - which can boast a more…

    11.94 miles away
  10. St Elvan's Church, Aberdare

    St Elvan's Church was started in 1851 and completed in 1852. It has for many years been…

    12.06 miles away
  11. Built in 1824, Cyfarthfa Castle is an impressive monument to the Industrial Revolution.…

    12.52 miles away
  12. Picturesque Cyfarthfa Park, covering 160 acres of beautiful parkland, sits at the foot of…

    12.53 miles away
Previous Next

Don't Miss

Don't Miss

Don't Miss