Taf Fechan Nature Reserve Circular Walk

This nature reserve is a 2.5km stretch of dramatic wooded limestone gorge cut by the River Taf Fechan, between the bridges of Pontsarn and Cefn Coed to the North of Merthyr Tydfil.

It lies adjacent to the eastern side of the popular Taff Trail and the reserve incorporates much of the area notified as Cwm Taf Fechan Woodlands Site of Special Scientific Interest. 

The reserve, managed by the Wildlife Trust of South and West Wales, has high nature conservation value and supports uncommon flora and fauna.

On the western bank of the river you can see a good population of broad leaved helleborine, as well as small leaved lime. In addition, there are large areas of grazed limestone grassland, some with bracken, with plentiful violets providing a suitable habitat for silver washed fritillary butterflies.

The Eastern bank sees a number of springs, with Tufa deposits, and the Gurnos quarry face is well developed, with facies and caves likely to be home to bats.

The reserve has a wide diversity of habitats, fast and slow flowing freshwater, open and dense deciduous woodland, calcareous and acidic grassland, exposed limestone cliff faces and old walls and tufa springs.

Signs of otters are regularly spotted, and the whole river stretch supports birds such as dipper and grey wagtail.  Goosander are regular in Winter, and evidence of badgers are often seen.

The Pont Sarn bridge by the Blue Pool (Pont-sarn-hir - the bridge of the long paved road) is the site of the Roman road crossing, travelling from Y Gaer at Brecon to the coastal fort at Cardiff. From the bridge, it went through Gurnos, towards Penydarren Park and on to Gelligaer.

There are the remains of an 18th-century corn mill on the eastern bank of the northernmost section of the reserve, one of four grinding mills that were located in the Taf Fechan valley. The original millstone grit millstone is nearby.

Further down the river are the remains of a fullers mill (a pandy) on the western bank just north of the timber bridge. Well-known local weavers, the Harris family, owned both these mills.

The Gurnos quarry supplied limestone for the furnaces of the Cyfarthfa Ironworks. Following the closure of the Ironworks, the quarry was planted with a selection of pine trees, with some still surviving on top of the cliff.

The tramway runs south from the quarry alongside the Taff, to beyond the Cefn Coed bridge. It was extended to reach the new Glamorganshire canal in 1792. It supplied the Cyfarthfa Ironworks with the all-important limestone needed for the ironworking process, and the stones forming the base of the tramway rails are a scheduled ancient monument, as is the Cyfarthfa leat which runs alongside it.