Talybont-on-Usk (Welsh: Tal-y-bont-ar-Wysg) is a huge community extending across the eastern slopes of the central Beacons.  The Geopark boundary cuts through the community - an asterisk (*) denotes all locations which lie outside the Geopark.

The lie of the land

Talybont ranges in height from about 112m* above sea level beside the River Usk downstream of the village of Talybont to the flat summit of Waun Rydd* which attains a height of 769m at SO 062206.  Other key hills include:

• Yr Allt* 565m (SO 057162) 
• Bryn* 562m (SO 071227)
• Tor y Foel* 551m (SO 114195)
• Allt yr Esgair* 393m (SO 126244)

The community extends across the Usk catchment including Glyn Collwn* down which flows the Caerfanell*.  This river is dammed above Aber village to form Talybont Reservoir*.  Talybont also includes a substantial part of the upper Taf Fechan catchment taking in Pentwyn and Pontsticill Reservoirs.

Solid rocks

The larger part of the area is underlain by Old Red Sandstone rocks.  These include the red siltstones and sandstones of the St Maughan's Formation in the Usk valley together with the overlying sandstones of the Senni Formation and Brownstones Formation which form much of the rest of the landscape.

The tops of Waun Rydd* and Craig y Fan Ddu* are capped by the harder sandstones of the Plateau Beds Formation.  these beds are found again south of Yr Allt* where they are overlain in turn by the Grey Grits.

The north-easterly continuation of the Neath Disturbance runs through Cwm Callan* and brings Carboniferous Limestone to the surface in the vicinity of Pentwyn Reservoir.

Legacy of the Ice Ages

The cwm below Craig Pwllfa* on the northeastern edge of the Waun Rydd plateau* is the only well-developed glacial cirque within the community.  It boasts a spectacular moraine.

Glacial till occupies various hollows and stretches of the valley sides of Glyn Collwn* though the lowest land is formed from alluvial silts and sands.

Major landslips have been identified beneath Cwar y Gigfran*, Allt Lwyd* and Allt yr Esgair* and also in the upper reaches of Cwm Banw*.  At least some of these are likely to have happened during or shortly after the end of the last ice age.

Archaeology

Iron Age forts sit atop the hills of Allt yr Esgair* and Yr Wenallt* which face each other across the Usk valley near the village of Talybont.

Maps

Geology

Sheet  231 'Merthyr Tydfil'  of the British Geological Survey’s 1:50,000 map series of England and Wales gives full coverage of both the bedrock geology and superficial deposits of that part of the Community which falls within the Geopark.   Coverage of the whole of the Community area is completed by sheets 213 'Brecon', '214 'Talgarth' and 232 'Abergavenny'.  BGS publishes memoirs and sheet explanations to compliment these maps.

General

The following Ordnance Survey maps cover the Community:

• Landranger sheet 160 'Brecon Beacons' (1:50,000 scale)
• Explorer sheet OL12 'Brecon Beacons National Park/Western area' (1:25,000 scale)

Public transport

Bus services operate along the A40 road between Brecon and Abergavenny.

See Traveline Cymru for bus and train services including stops, timetables and route-planning information.