The River Usk rises on the northern slopes of the Black Mountain, 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.
The Ebbw River is a river in South Wales which gives its name to the town of Ebbw Vale. The Ebbw River is joined by the Ebbw Fach River at Aberbeeg. The Ebbw Fach is itself fed by a left-bank tributary, the River Tyleri.
Fan Fawr is a mountain in the Fforest Fawr section of the Brecon Beacons National Park, in Powys, Wales and over 734 m (2,408 ft) high.
The River Clydach is a short, steep and fast-flowing river in Monmouthshire and the county borough of Blaenau Gwent in south Wales. It lies within the Brecon Beacons National Park. It is around 10 kilometres (6 mi) in length.
The Afon Crai is a river in Powys, Wales rising in the Fforest Fawr section of the Brecon Beacons National Park and flowing north into the River Usk. The headwaters known as Blaen-crai flow north from Bwlch Bryn-rhudd, a col between the Crai valley and the upper Swansea Valley for 2 km into the Cray Reservoir. The river emerges from below the dam to flow a further 8 km through the dispersed settlement of Crai.
The Afon Senni is a river in Powys, Wales which rises in the Fforest Fawr section of the Brecon Beacons National Park and flows northwards for 11 kilometres (7 mi) to a confluence with the River Usk at Sennybridge.
The Caerfanell is a river which rises in the central section of the Brecon Beacons National Park in Powys, Wales. It rises as Blaen Caerfanell on the plateau of Gwaun Cerrig Llwydion and drops steeply down southeastwards into the head of Glyn Collwn before turning east then north-east into Talybont Reservoir. It emerges from the hydro turbine beneath the dam just above the village of Aber and continues northwards to its confluence with the River Usk at the hamlet of Llansantffraed.
The Grwyne Fawr is a river in the Brecon Beacons National Park in south Wales. A section of it forms the administrative border between Powys and Monmouthshire and also of the historic counties of Brecon and Monmouth. The river and its major tributary the Grwyne Fechan flow into the River Usk at Glangrwyney.
The Rhiangoll is a river in the Brecon Beacons National Park in Powys, Wales. It rises on the western slopes of Waun Fach, highest point of the Black Mountains and drops steeply down to the west into the north–south valley through which the A479 runs between Talgarth and the hamlet of Tretower and through the village of Cwmdu. It is joined by various minor tributary streams on its left bank including the Ffinnant, Nant yr Ychen, Nant-y-fedw and Nantygarreg, all of which rise on the flanks of the ridge extending between the Pen Trumau spur of Waun Fach and Pen Gloch-y-pibwr. Two tributary streams flowing from Mynydd Troed and Mynydd Llangorse enter on its right bank as does Nant Ewyn east of the village of Bwlch.
The Afon Llynfi is a short river in the county of Powys, south Wales. A tributary of the River Wye, it runs approximately south to north just to the west of the Black Mountains and partly within the Brecon Beacons National Park. The river rises as a small stream to the west of the village of Bwlch and flows north for two miles into Llangorse Lake. It leaves the lake just to the southwest of the village of Llangors and follows a course past the hamlets of Trefecca and Tredustan. The river then travels between the twin villages of Talgarth and Bronllys, forming the boundary of the national park in part. It then flows northeast past the village of Three Cocks before entering the River Wye just upstream of Glasbury Bridge.
The River Honddu is a river in the county of Powys, mid Wales. Early recorded versions of the name are of the form Hothenei and hodni which are believed to contain the Welsh adjective 'hawdd', meaning 'pleasant' or 'easy', together with a suffix -ni. Later forms such as Honddey and Honthy have undergone metathesis whereby -ddn- became -ndd-.
The Afon Hydfer is a short river in Powys in the west of the Brecon Beacons National Park, south Wales. Its headwaters rise on the northeastern slopes of the Black Mountain as the streams named Trinant, Nant y Cadno, Nant yr Erydr and Crognant joining to flow down Cwm yr Afon on the western edge of Glasfynyd Forest. The river turns east at Blaenau Uchaf, then northeast through Cwm Hydfer and joins the River Usk just below Pont ar Hydfer. Other tributaries of the Hydfer include the streams of Nant Cil-y-clawdd, Nant Crinog and Nant Meity.
Glasfynydd Forest is an extensive area of coniferous plantations in the west of the Brecon Beacons National Park in Wales. It straddles the border between the counties of Powys and Carmarthenshire.
The Nant Brân is a short river which rises on the southern slopes of Mynydd Epynt in Powys, Wales. The word 'brân' means 'crow' in Welsh: the name may therefore allude to the dark colour of its waters.
Merthyr Cynog is a hamlet and a community in the modern county of Powys, Wales, in the historic county of Brecknockshire. The population of the community at the 2011 Census was 245.
Llanfrynach is a village and community in the county of Powys, Wales, and the historic county of Brecknockshire. The population of the community as taken at the 2011 census was 571. It lies just to the southeast of Brecon in the Brecon Beacons National Park. The village sits astride the Nant Menasgin, a right bank tributary of the River Usk. The B4558 passes just to its north and the Monmouthshire and Brecon Canal also passes around the village. The Welsh name signifies the 'church of Brynach'. The community includes the hamlets of Llanhamlach and Groesffordd.
The Usk Bridge in Brecon, Powys, Wales is the town's oldest route over the River Usk. It carries the B4601 road, formerly the A40, between Brecon and Llanfaes.
Yscir with Honddu Isaf and Llanddew is the name of an electoral ward in southern Powys, Wales. It covers five local government communities and elects a councillor to Powys County Council.
Glangrwyney or Glangrwyne is a village 2 miles (3.2 km) southeast of Crickhowell in Powys, Wales. The village is where the Grwyne Fawr has its confluence with the River Usk, southeast of the Sugar Loaf and at the junction of the road from Gilwern with the A40 trunk road. Glangrwyney is in the Vale of Grwyney Community for administrative purposes. The village is built upon the sands and gravels of a dissected alluvial fan which extends into the floodplain of the Usk, together with till derived from the former Usk Valley glacier.
The Afon Cilieni is a short river which rises on the southern slopes of Mynydd Epynt in Powys, Wales. The name may mean ' the river rising in a small nook'.
