|Terrig (Afon Terrig)|
The Terrig near Leeswood Old Hall.
|Name origin: From Welsh terydd, "swift", or terig, "violent, harsh"|
|- location||Llyn Cyfynwy, near Graianrhyd, Denbighshire|
|- elevation||370 m (1,214 ft)|
|- location||confluence with River Alyn, Flintshire|
|- elevation||95 m (312 ft)|
The river rises at Llyn Cyfynwy near Graianrhyd village in the community of Llanarmon-yn-Ial, Denbighshire, about three miles from the source of the River Alyn. It then flows northwards and eastwards, forming the boundary between the old parishes of Nercwys and Treuddyn. At Nant-y-Mynydd it is joined by several small springs from Mynydd Ddu, and finally itself joins the River Alyn at Pontblyddyn, Flintshire.
The Terrig is a habitat for brown trout. Its name is derived from its rapid flow after times of heavy rain; Thomas Pennant, in his Tours in Wales, described it as "the Terrig, or the violent, [...] often of a tremendous swell and fury".
- Cambridge County Geographies: Flintshire, Cambridge University Press, p.25
- Pennant, T. Tours in Wales, Volume 2, Wilkie and Robinson, 1810, p.44