The Afon Ysgir is a

river A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of wate ...

which rises on the southern slopes of

Mynydd Epynt Mynydd Epynt () is a former community and upland area in Powys, Wales. The Ministry of Defence controversially evicted the community of Mynydd Epynt in 1940, creating what is now the core of the Sennybridge Training Area (SENTA), the largest mil ...

Powys Powys (; ) is a Local government in Wales#Principal areas, county and Preserved counties of Wales, preserved county in Wales. It is named after the Kingdom of Powys which was a Welsh succession of states, successor state, petty kingdom and princi ...

Wales Wales ( cy, Cymru ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by England to the Wales–England border, east, the Irish Sea to the north and west, the Celtic Sea to the south west and the ...

. The tributaries known as Ysgir Fawr and Ysgir Fechan flow past the hamlets of Pont Rhyd-y-berry and

Merthyr Cynog 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. The Welsh name signifies the 'shrine of Cynog'. The grade II* li ...

to combine at Pont-faen and continue past the village of Battle to join the

River Usk The River Usk (; cy, Afon Wysg) 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 fl ...

at Aberyscir. Its upper reaches are within the military training area of

SENTA Senta ( sr-cyrl, Сента, ; Hungarian: ''Zenta'', ; Romanian: ''Zenta'') is a town and municipality located in the North Banat District of the autonomous province of Vojvodina, Serbia. It is situated on the bank of the Tisa river in the ge ...

, the British Army's

Sennybridge Sennybridge ( cy, Pontsenni) is a village in the historic county of Brecknockshire, Wales, now within the unitary authority area of Powys, situated some from Cardiff and from Swansea. It lies west of Brecon on the A40 trunk road to Llandov ...

Training Area. Near its mouth is a

motte A motte-and-bailey castle is a European fortification with a wooden or stone keep situated on a raised area of ground called a motte, accompanied by a walled courtyard, or bailey, surrounded by a protective ditch and palisade. Relatively easy to ...

, the historic church at Aberyscir and east of the river, the

Roman fort In the Roman Republic and the Roman Empire, the Latin word ''castrum'', plural ''castra'', was a military-related term. In Latin usage, the singular form ''castrum'' meant 'fort', while the plural form ''castra'' meant 'camp'. The singular and ...

of CICVCIVM or

Brecon Gaer Y Gaer () is a Roman fort situated near modern-day Brecon in Mid Wales, United Kingdom. Y Gaer is located at (Landranger 160). History Y Gaer was built around AD 75 and sits on a crossroads of Roman roads in the valley of the River Usk at a ...

. Along with other tributaries of the Usk, the river is designated as a

special area of conservation A Special Area of Conservation (SAC) is defined in the European Union's Habitats Directive (92/43/EEC), also known as the ''Directive on the Conservation of Natural Habitats and of Wild Fauna and Flora''. They are to protect the 220 habitats and ap ...

or 'SAC' for various species of fish including

lamprey Lampreys (sometimes inaccurately called lamprey eels) are an ancient extant lineage of jawless fish of the order Petromyzontiformes , placed in the superclass Cyclostomata. The adult lamprey may be characterized by a toothed, funnel-like s ...

, the

twaite shad The twait shad or twaite shad (''Alosa fallax'') is a species of fish in the family Clupeidae. It is found in the eastern Atlantic Ocean and the Mediterranean Sea and is an anadromous fish which lives in the sea but migrates into fresh water to s ...

and the

European bullhead The European bullhead (''Cottus gobio'') is a freshwater fish that is widely distributed in Europe, mainly in rivers. It is a member of the family Cottidae, a type of sculpin. It is also known as the miller's thumb, freshwater sculpin, common bu ...

.http://www.ccw.gov.uk Countryside Council for Wales website

References

{{DEFAULTSORT:Ysgir Afon Ysgir Rivers of the Brecon Beacons National Park Rivers of Powys