The River Dysynni () is a

river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...

in mid

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

. Its source is the

Tal-y-llyn Lake Tal-y-llyn Lake, (), also known as Talyllyn Lake and Llyn Myngul, is a large glacial ribbon lake in Gwynedd, North Wales. It is formed by a post-glacial massive landslip damming up the lake within the glaciated valley. The hamlet of Talyllyn ...

() just south of the

Cadair Idris Cadair Idris or Cader Idris is a mountain in the Meirionnydd area of Gwynedd, Wales. It lies at the southern end of the Snowdonia National Park near the town of Dolgellau. The peak, which is one of the most popular in Wales for walkers and hikin ...

massif and its mouth is in the

Cardigan Bay Cardigan Bay () is a large inlet of the Irish Sea, indenting the west coast of Wales between Bardsey Island, Gwynedd in the north, and Strumble Head, Pembrokeshire at its southern end. It is the largest bay in Wales. Geography Cardigan Bay ha ...

area of the

Irish Sea The Irish Sea is a body of water that separates the islands of Ireland and Great Britain. It is linked to the Celtic Sea in the south by St George's Channel and to the Inner Seas off the West Coast of Scotland in the north by the North Ch ...

to the north of

Tywyn Tywyn (; ), formerly spelled Towyn, is a town, community, and seaside resort on the Cardigan Bay coast of southern Gwynedd, Wales. It was previously in the historic county of Merionethshire. It is famous as the location of the Cadfan Stone, a ...

. It measures about in length. Dysynni estuary 01

Course

The River Dysynni flows from the western end of

in a southwesterly direction to its confluence with the Nant Gwernol at

Abergynolwyn Abergynolwyn () is a village in southern Gwynedd, Wales, located at the confluence of the Nant Gwernol and the Afon Dysynni. The population of the community which is named after the village of Llanfihangel-y-Pennant was 339 at the 2011 census ...

. From here it flows in a northwesterly direction to its confluence with the Afon Cader, from where it resumes its southwesterly direction, meandering through a broad valley. It is joined here by its tributary, the

Afon Fathew The Afon Fathew () is a river in Gwynedd, north-west Wales. The river is downstream from the Dolgoch Falls which is a popular nature site, and is followed for much of its course by the Talyllyn Railway. Name The basic name of the river in W ...

, which flows from near Dolgoch and joins it to the east of

, near

Bryncrug Bryncrug (), sometimes spelt Bryn-crug, is a village and community (Wales), community in Gwynedd, Wales. Afon Fathew flows through the village and into the River Dysynni. The village is situated to the north east of the town of Tywyn, at the ju ...

. The river enters

through the

Broad Water Broad Water, or Broadwater ( Welsh: ''Aber Dysynni'') is a salt water lagoon near Tywyn, Wales formed from the silted up estuary of the River Dysynni. In the eighteenth and nineteenth centuries, the estuary was used by the shipbuilding indust ...

lagoon to the north of Tywyn, near

Tonfanau Tonfanau is a coastal village in the Community (Wales), community of Llangelynnin, Gwynedd, Llangelynnin, in Gwynedd (formerly Merionethshire), Wales. It is north of Tywyn. The village is served by Tonfanau railway station. During the Second Wo ...

. The river is interesting geologically because it exhibits river capture. This is likely to be as a result of river damming during a glacial period. The upper course of the river follows a

fault line In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

but at Abergynolwyn must have been blocked by a major

landslide Landslides, also known as landslips, rockslips or rockslides, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, mudflows, shallow or deep-seated slope failures and debris flows. Landslides ...

, the scar from which can still be seen on the side of the valley. The valley below here is blocked by debris on a rock base. The River Dysynni was thus forced to adopt a new course, and pushed its way through the hills northwestwards to find a new course in the parallel valley to the north.

Walking

The Dysynni Valley is popular with walkers. It is a scenic valley, with the

massif to the north and the huge rock face of Craig yr Aderyn to the south. The valley contains the ruins of

Castell y Bere Castell y Bere is a Wales, Welsh castle near Llanfihangel-y-pennant, Abergynolwyn, Llanfihangel-y-pennant in Gwynedd, Wales. Constructed by Llywelyn the Great in the 1220s, the stone castle was intended to maintain his authority over the local ...

near Llanfihangel-y-Pennant. There are several walking routes, one being a path from

alongside the Afon Fathew to the

Tributaries

* Nant Gwernol * Afon Cader *

References

External links

www.geograph.co.uk : photos of the River Dysynni
{{authority control Abergynolwyn Bryncrug Llanfihangel-y-Pennant Llangelynin, Gwynedd Tywyn Dysynni Dysynni