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 Avon, Falkirk the Firth. The Avon flows through the Avon Gorge and forms the boundary between Falkirk and West Lothian council areas. It is 19 miles (31 km) in length. Like other rivers of this name throughout Britain, the name Avon simply means 'river', derived from Scottish Gaelic "abhainn", or British (i.e. Old Welsh) "afon". River Avon, Falkirk The Avon is a river largely in the Falkirk council area of Scotland. It originates, near some wind turbines, at what modern maps call Avonhead Cottage south of Upperton just west of Longriggend. Older maps show it near Avonhead just west of "Avonhead Rows"