The townland of Corryolus (Irish: Coraidh Eolais, Weir of Eolus), lying on the junction of the Shannon and Boyle river's, directly north of Carrick on Shannon, obtained its name from Eolus from whom the 'Muintir Eolais' are directly descended. In the remote mountainous Cuilcagh-Anierin uplands, the oligotrophic lake named Lough Munter Eolas marks a borderline between west Cavan and south Leitrim.