River Brenig (also Brennig), a tributary of the River Teifi . According to the 2001 Census , Tregaron's population was 1,183 of whom 68.8% spoke Welsh fluently, including 100% of the 15-year-old age group. Euskara: Tregaron Galesko Ceredigion konderriko azoka udalerri bat da, Teifi ibaiaren ur emalea den Brenig ibairen ertzean