Native name An Eithne Basin size 1,254 km (484 sq mi) Source Lough Sheelin | Country Ireland Length 89 km River system River Shannon | |
 | ||
Etymology From the mythological figure Ethniu Main source Lough Sheelin, County Cavan–Longford River mouth Atlantic via the River Shannon | ||
The River Inny (Irish: An Eithne) is a river within the Shannon River Basin in Ireland. The Inny is 40 miles (64 km) in length
It begins as a stream on Patrickstown hill, one of the peaks which form the Loughcrew complex of megalithic tombs, near Oldcastle in County Meath and marks the boundary between Meath and Cavan for about four miles before it enters Lough Sheelin in County Cavan. From Lough Sheelin it forms the boundary between Westmeath and Cavan, and flows under the bridge of Finea into Lough Kinale where counties Cavan and Westmeath meet Longford. From there it forms much of the boundary between Longford and Westmeath but enters Westmeath near Streete and flows into Lough Derravaragh. It then flows near the village of Ballinalack and crosses into County Longford near Abbeyshrule, where the Whitworth aqueduct suspends the Royal Canal above the river, and pumps supply the canal with water. At nearby Tenelick the mythological Princess Eithne drowned in the rapids, giving her name to the river, which powered two mills here for many years. It continues past Newcastle House to Ballymahon, the largest town located on the Inny. It again forms the county line between Longford and Westmeath, flowing westwards into Lough Ree to meet the boundary with County Roscommon. From there it becomes part of the River Shannon, flowing through Athlone to enter the Atlantic Ocean.