The Nant Ceiswyn (sometimes known as the ''Afon Ceiswyn'') is a small

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 ...

Mid Wales Mid Wales ( cy, Canolbarth Cymru or simply ''Y Canolbarth'', meaning "the midlands") or Central Wales refers to a region of Wales, encompassing its midlands, in-between North Wales and South Wales. The Mid Wales Regional Committee of the Senedd ...

. It flows from the northern flank of

Mynydd Dolgoed Mynydd Dolgoed or Craig Portas is a mountain in southern Snowdonia, Wales. It is a long ridge running from a low summit between the valleys of the Afon Angell and the Nant Ceiswyn, north east to the cliff of Craig Portas above Dinas Mawddwy. The ...

down to Pont Cymerau, north-east of

Aberllefenni Aberllefenni is a village in the south of Gwynedd, Wales. It lies in the historic county of Merionethshire/ Sir Feirionnydd, in the valley of the Afon Dulas, and in the Community of Corris. Government The village has a community council. The ...

. Here it joins the

Nant Llwydiarth The Nant Llwydiarth is a small river in Mid Wales. It flows from the southern flank of Mynydd Hendre-ddu down to Pont Cymerau, north-east of Aberllefenni. Here it joins the Nant Ceiswyn to form the Afon Dulas that flows south to the Afon Dyfi ...

to form the

Afon Dulas The Afon Dulas, or North Dulas, is a river forming the border between Merionethshire/Gwynedd and Montgomeryshire/Powys in Wales. Another river called Afon Dulas joins the Dyfi from the south, upstream of its confluence with the North Dulas: loca ...

that flows south to the Afon Dyfi. There was an ancient bridge at Pont Cymerau. The valley of the river is often known as ''Cwm Ratgoed'' (or ''Ralltgoed''), after the Ratgoed slate quarry about two miles north of Pont Cymerau. The quarry was connected to the

Corris Railway The Corris Railway ( cy, Rheilffordd Corris) is a narrow gauge preserved railway based in Corris on the border between Merionethshire (now Gwynedd) and Montgomeryshire (now Powys) in Mid-Wales. The line opened in 1859 as a horse tramway, runni ...

at Aberllefenni by the horse-worked Ratgoed Tramway, which crossed the river as it passes Cymerau Quarry. To the east of the valley is

Mynydd Ceiswyn Mynydd Ceiswyn is a mountain in Wales. It is the peak south of Waun-oer in the Dyfi Hills. On the east side of the mountain is the valley of the Nant Ceiswyn, and Cwm Hengae Cwm Hengae is a valley that runs roughly north-west from the village ...

, part of the chain of ridges running southwards from

Maesglase Maesglase is a mountain in Snowdonia, North Wales, situated approximately four miles to the south-west of Aran Fawddwy. It is the highest of the Dyfi Hills. It can be reached by an easy but steep walk through the forestry from Dinas Mawd ...

References

{{authority control Rivers of Gwynedd Rivers of Snowdonia Aberllefenni