Killywillin () is a townland in the civil parish of Templeport, County Cavan, Ireland. It lies in the Roman Catholic parish of Templeport and barony of Tullyhaw. Geography Killywillin is bounded on the north by Gortaclogher and Killymoriarty townlands, on the west by Killyran townland, on the south by Ballymagauran and Derryragh townlands and on the east by Porturlan townland. Its chief geographical features are Killywillin Lough, the River Blackwater, County Cavan, spring wells and a quarry. Killywillin is traversed by the regional R205 road (Ireland), minor roads, rural lanes and the disused Cavan and Leitrim Railway. The townland covers 202 statute acres. Etymology There was a medieval corn-mill on the River Blackwater, from which the townland derives its name. History In medieval times the McGovern barony of Tullyhaw was divided into economic taxation areas called ballibetoes, from the Irish Baile Biataigh (Anglicized as 'Ballybetagh'), meaning 'A Provisioner's Town or Settlement'. The original purpose was to enable the farmer, who controlled the baile, to provide hospitality for those who needed it, such as poor people and travellers. The ballybetagh was further divided into townlands farmed by individual families who paid a tribute or tax to the head of the ballybetagh, who in turn paid a similar tribute to the clan chief. The steward of the ballybetagh would have been the secular equivalent of the erenagh in charge of church lands. There were seven ballibetoes in the parish of Templeport. Killywillin was located in the ballybetagh of Ballymagauran. The historical spellings of the ballybetagh are Ballymackgawran & Ballimacgawran (Irish = Baile Mhic Shamhráin = McGovern's Town). The earliest known mention of Killywillin is in the Irish annals for 1495 A.D. concerning the death of the McGovern clan chief, Feidhlimidh Mág Samhradháin, the First, who ruled from 1478 to 15 Feb 1495. The Annals of Ulster state- Mag Samradhain, namely, Feidhlimidh, son of Thomas, son of Ferghal, son of Thomas, son of Brian the Bregian, namely, chief of Tellach-Eathach, was drowned at the crannóg of Killywillin Lough (loch crannoigi Caille an Mhuilinn), the feast day of Berach, Sunday, this year and his other brother, namely, Domnall Gapped tooth, was made Mag Samradhain. The Annals of the Four Masters state- Magauran (Felim, the son of Thomas, son of Brian Breaghach), Chief of Tullyhaw, was drowned at the crannóg of Killywillin Lough (Loch Crannóicce Caille an Mhuilinn); and Donnell Bearnagh, his brother, took his