"TRÊVILAN (TRÊV-ILAR), a parish in the lower division of the hundred of ILAR, county of CARDIGAN, SOUTH WALES, 7 miles (N. by W.) from Lampeter, containing 313 inhabitants. This parish is pleasantly situated in the Vale of Aëron and on the high road from Lampeter to Aberystwith. The surrounding country is boldly varied, and the scenery is in some parts picturesque. In the southern part of the parish is the small village of`Talsarn, deriving its name from a branch of a Roman road or causeway which terminated here, and which is situated on the bank of the river Aëron .."
[From Samuel Lewis's A Topographical Dictionary of Wales 1833]