The Afon Erch is a short river on the

Llŷn peninsula The Llŷn Peninsula ( cy, Penrhyn Llŷn or , ) extends into the Irish Sea from North West Wales, south west of the Isle of Anglesey. It is part of the historic county of Caernarfonshire, and historic region and local authority area of Gwynedd. Mu ...

Gwynedd Gwynedd (; ) is a county and preserved county (latter with differing boundaries; includes the Isle of Anglesey) in the north-west of Wales. It shares borders with Powys, Conwy County Borough, Denbighshire, Anglesey over the Menai Strait, and C ...

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 ...

. It arises on the slopes of Bwlch Mawr, flowing south and southwest towards the hamlet of Llwyndyrys where it turns abruptly eastwards and curves around to the south, passing to the east of Y Ffor at Rhyd-y-gwystl. It continues in a south-southwest direction towards

Abererch Aber-erch (Welsh language, Welsh for "Mouth of the Afon Erch, Erch") is a small village and former civil parish on the Llŷn Peninsula in the Wales, Welsh county of Gwynedd. The village lies approximately east of Pwllheli. A river, the Afon Erc ...

where despite the village name, it does not enter the sea but flows west parallel to the coast for 1 mile to

Pwllheli Pwllheli () is a market town and community of the Llŷn Peninsula ( cy, Penrhyn Llŷn) in Gwynedd, north-western Wales. It had a population of 4,076 in 2011 of whom a large proportion, 81%, are Welsh language, Welsh speaking. Pwllheli is the pl ...

. The Afon Rhyd-hir (translates from

Welsh Welsh may refer to: Related to Wales * Welsh, referring or related to Wales * Welsh language, a Brittonic Celtic language spoken in Wales * Welsh people People * Welsh (surname) * Sometimes used as a synonym for the ancient Britons (Celtic peop ...

as 'river of the long ford') joins the Afon Erch within the tidal basin of Pwllheli Harbour. Its headwaters gather to the south of

Llithfaen Llithfaen is a Medium Sized Village on the Llŷn Peninsula in Gwynedd, Wales, in the historic county of Caernarfonshire , HQ= County Hall, Caernarfon , Map= , Image= Flag , Motto= ...

and flow south past

Llannor Llannor is a village, parish and community located on the Llŷn Peninsula (Welsh: ''Penrhyn Llŷn'') in the Welsh county of Gwynedd. Historically in Caernarfonshire, it lies 1.7 miles (2.8 km) north of Pwllheli and 18.0 miles (29.0 k ...

to approach Pwllheli from the west. It is joined by the Afon Penrhos immediately west of the town, having originated around the extensive

bog A bog or bogland is a wetland that accumulates peat as a deposit of dead plant materials often mosses, typically sphagnum moss. It is one of the four main types of wetlands. Other names for bogs include mire, mosses, quagmire, and muskeg; a ...

of Cors Geirch, a national nature reserve. Parts of the courses of each of these rivers occupy valleys that were formed by

glacial meltwater Meltwater is water released by the melting of snow or ice, including glacial ice, tabular icebergs and ice shelves over oceans. Meltwater is often found in the ablation zone of glaciers, where the rate of snow cover is reducing. Meltwater can b ...

. The uppermost Penrhos is a

misfit stream A misfit stream is a river that is either too large or too small to have eroded the valley or cave passage in which it flows. This term is also used for a stream or river with meanders that obviously are not proportional in size to the meanders ...

within its valley. The name of the Erch either signifies 'dappled/dark' or is possibly a personal name. Until the 16th century Aber-erch did sit at the point at which the river entered the sea but the

longshore drift Longshore drift from longshore current is a geological process that consists of the transportation of sediments (clay, silt, pebbles, sand, shingle) along a coast parallel to the shoreline, which is dependent on the angle incoming wave direction ...

of the sands of Morfa Abererch diverted it west thereafter.

References

Rivers of Gwynedd {{Wales-river-stub