Y Felinheli (), formerly known in English as Port Dinorwic, is a village and community beside the Menai Strait ( or Afon Menai) between Bangor and Caernarfon in Gwynedd, northwest Wales. History Toponymy Etymologically, its name comes from the Welsh y meaning the, melin meaning mill and heli, meaning brine/salt-water/sea. An alternative interpretation is from Y Felin Heulyn, "the mill on the River Heulyn", which refers to the river that runs into the village. Origins Y Felinheli has its origins in two hamlets, Tafarngrisiau near St Mary's Church and Aberpwll to the north-east where there was a mill on the Afon Heulyn. The mill was rebuilt closer to the sea in 1633 and gave its name to the settlement. The area was largely agricultural until the area was transformed by slate quarrying in the 19th century. A new dock was built in 1828 when lime was extracted at Brynadda and slate and lime were loaded and culm (coal dust or anthracite slack) was brought in to fire the lime kilns. The owners of the Vaynol Estate, the Assheton Smiths, owned most of the land in Y Felinheli and developed the Dinorwic Quarry in the late 18th century, They also built the harbour to export slate transported to the quay by the Dinorwic Railway, a narrow gauge railway that was subsequently replaced by the Padarn Railway. Industrial expansion gave Y Felinheli (Felin-hely, 1838) the alternative name Port Dinorwig or Port Dinorwic. Harbour The harbour is a centre for pleasure boating and sailing. It has moorings, a marina and yacht support businesses, including rigging, sail making and boatyards. The boatyard was constructed before the Second World War for building landing craft. Its slipway, probably the largest in North Wales is in private ownership, is usable at most states of tide. The local sailing club organizes dinghy racing. Demographics Population Number The population of the village was 2,284 at the 2011 Census. According to the 2021 Census, Y Felinheli's population was 2,330. Density In June 2018, the population density in Y Felinheli was , compared to for Gwynedd. Languages Welsh According to the United Kingdom Census 2021, 68.3 per cent of all usual residents aged 3+ in Y Felinheli can speak Welsh. 78.6 per cent of the population noted that they could speak, read, write or understand Welsh. The 2011 census noted 64.3 per cent of all usual residents aged 3 years and