River Usk River Usk The River Usk (; ) rises on the northern slopes of the Black Mountain ("y Mynydd Du"), Wales, 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 beyond
River Dore River Dore The River Dore (Welsh: "Afon Aur" lit: 'the River of Gold') is a tributary of the River Monnow in Herefordshire, England. It rises on Cusop Hill, in the foothills of the Black Mountains, close to the border between England and Wales. It flows for through the villages of Dorstone, Peterchurch, Vowchurch, Abbey Dore and Pontrilas, before reaching the Monnow near Llangua. The Monnow itself is a tributary which flows into the River Wye at Monmouth. The name Dore probably derives from the Welsh word "dŵr", meaning "water". The word was later interpreted by the Norman French as ""d'or"",