Nedd Fechan
Encyclopedia
The Nedd Fechan or 'Little Neath' is a river in the county
of Powys
, south Wales
, Great Britain. It rises on the eastern slopes of Fan Gyhirych
in the Fforest Fawr
section of the Brecon Beacons National Park and flows south for 12km / 7 mi to join with the Afon Mellte at Pontneddfechan, their combined waters continuing as the River Neath
(Welsh
Afon Nedd) to the sea near Swansea
. The only significant tributary of the Nedd Fechan is the Afon Pyrddin
which joins it at Pwll Du ar Byrddin ('the black pool of the Pyrddin').
as far as Blaen-nedd-isaf where they encounter the Carboniferous Limestone
outcrop. The river then continues through a wooded gorge for the remainder of its course. The section downstream of Pont Rhyd-y-cnau is cut in sandstones and mudstones of the Millstone Grit
series. The section between Pont Melin-fach and the confluence of the river with the Afon Pyrddin is perhaps the most dramatic as the river plunges over several falls of which Sgwd Ddwli and Sgwd Pedol are the most acclaimed. Each of the falls is associated with faults bringing harder sandstone beds into contact with the more readily eroded mudstones.
which also covers neighbouring river gorges. It also forms a part of a larger special area of conservation
designated for its rare bryophyte
flora.
s are visible on both sides of the river, most of which were served by horse-drawn tramways. The former tramways now provide easy access along this lower section of the gorge.
County
A county is a jurisdiction of local government in certain modern nations. Historically in mainland Europe, the original French term, comté, and its equivalents in other languages denoted a jurisdiction under the sovereignty of a count A county is a jurisdiction of local government in certain...
of Powys
Powys
Powys is a local-government county and preserved county in Wales.-Geography:Powys covers the historic counties of Montgomeryshire and Radnorshire, most of Brecknockshire , and a small part of Denbighshire — an area of 5,179 km², making it the largest county in Wales by land area.It is...
, south Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
, Great Britain. It rises on the eastern slopes of Fan Gyhirych
Fan Gyhirych
Fan Gyhirych is a mountain in the Fforest Fawr section of Brecon Beacons National Park in south Wales. It lies within the county of Powys, formerly Brecknockshire....
in the Fforest Fawr
Fforest Fawr
Fforest Fawr is the name given to an extensive upland area in the county of Powys, Wales. Formerly known as the 'Great Forest of Brecknock' in English, it was a royal hunting area for several centuries but is now used primarily for sheep grazing, forestry, water catchment and recreation...
section of the Brecon Beacons National Park and flows south for 12km / 7 mi to join with the Afon Mellte at Pontneddfechan, their combined waters continuing as the River Neath
River Neath
River Neath is a river in south Wales running south west from its source in the Brecon Beacons National Park to its mouth at Baglan Bay below Briton Ferry on the east side of Swansea Bay.Several minor rivers rise on the southern slopes of Fforest Fawr...
(Welsh
Welsh language
Welsh is a member of the Brythonic branch of the Celtic languages spoken natively in Wales, by some along the Welsh border in England, and in Y Wladfa...
Afon Nedd) to the sea near Swansea
Swansea
Swansea is a coastal city and county in Wales. Swansea is in the historic county boundaries of Glamorgan. Situated on the sandy South West Wales coast, the county area includes the Gower Peninsula and the Lliw uplands...
. The only significant tributary of the Nedd Fechan is the Afon Pyrddin
Afon Pyrddin
The Afon Pyrddin is a river forming the boundary between the county of Powys and the county borough of Neath Port Talbot in south Wales, Great Britain. It also forms a part of the boundary of the Brecon Beacons National Park...
which joins it at Pwll Du ar Byrddin ('the black pool of the Pyrddin').
Geology
The headwaters of the river run over Old Red SandstoneOld Red Sandstone
The Old Red Sandstone is a British rock formation of considerable importance to early paleontology. For convenience the short version of the term, 'ORS' is often used in literature on the subject.-Sedimentology:...
as far as Blaen-nedd-isaf where they encounter the Carboniferous Limestone
Carboniferous limestone
Carboniferous Limestone is a term used to describe a variety of different types of limestone occurring widely across Great Britain and Ireland which were deposited during the Dinantian epoch of the Carboniferous period. They were formed between 363 and 325 million years ago...
outcrop. The river then continues through a wooded gorge for the remainder of its course. The section downstream of Pont Rhyd-y-cnau is cut in sandstones and mudstones of the Millstone Grit
Millstone Grit
Millstone Grit is the name given to any of a number of coarse-grained sandstones of Carboniferous age which occur in the Northern England. The name derives from its use in earlier times as a source of millstones for use principally in watermills...
series. The section between Pont Melin-fach and the confluence of the river with the Afon Pyrddin is perhaps the most dramatic as the river plunges over several falls of which Sgwd Ddwli and Sgwd Pedol are the most acclaimed. Each of the falls is associated with faults bringing harder sandstone beds into contact with the more readily eroded mudstones.
Habitat Protection
The entire gorge section of the Nedd Fechan valley is protected as part of a larger site of special scientific interestSite of Special Scientific Interest
A Site of Special Scientific Interest is a conservation designation denoting a protected area in the United Kingdom. SSSIs are the basic building block of site-based nature conservation legislation and most other legal nature/geological conservation designations in Great Britain are based upon...
which also covers neighbouring river gorges. It also forms a part of a larger special area of conservation
Special Area of Conservation
A Special Area of Conservation is defined in the European Union's Habitats Directive , also known as the Directive on the Conservation of Natural Habitats and of Wild Fauna and Flora...
designated for its rare bryophyte
Bryophyte
Bryophyte is a traditional name used to refer to all embryophytes that do not have true vascular tissue and are therefore called 'non-vascular plants'. Some bryophytes do have specialized tissues for the transport of water; however since these do not contain lignin, they are not considered to be...
flora.
Archaeology
Downstream of the Pyrddin confluence is abundant evidence of the former silica rock mining industry. A number of aditAdit
An adit is an entrance to an underground mine which is horizontal or nearly horizontal, by which the mine can be entered, drained of water, and ventilated.-Construction:...
s are visible on both sides of the river, most of which were served by horse-drawn tramways. The former tramways now provide easy access along this lower section of the gorge.