Nant Gwys

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

The Nant Gwys is a river flowing off the Black Mountain (Y Mynydd Du) in Powys, Wales. Its tributaries Gwys Fawr and the Gwys Fach flow south from Banwen Gwyn and Bwlch y Ddeuwynt respectively and join forces to form the Nant Gwys proper which then flows for about 5 km / 3 mi to its confluence with the Afon Twrch at Cwm-twrch-Uchaf.

The upper reaches of the river and its tributaries lie within the Brecon Beacons National Park (Parc Cenedlaethol Bannau Brycheiniog) and within Fforest Fawr Geopark.[1] The river is one of several which run down the southward directed dip-slopes of the Black Mountain (Y Mynydd Du) passing from the Millstone Grit outcrop onto the mudstones of the Carboniferous Coal Measures.[2]

The name translates from Welsh as 'sow stream', presumably in reference to the neighbouring Afon Twrch or 'boar river'.

External links[edit]


  1. ^ Ordnance Survey Explorer map OL12 'Brecon Beacons National Park: western area
  2. ^ British Geological Survey 1:50,000 map sheets 230 'Ammanford' & 231 'Merthyr Tydfil' & memoir accompanying latter

Coordinates: 51°47′13″N 3°48′08″W / 51.78685°N 3.80213°W / 51.78685; -3.80213