The River Brosna is a significant Irish midland river stretching approximately 79 kilometers through County Westmeath and County Offaly, forming part of the greater Shannon River Basin. Rising from Lough Owel north of Mullingar, the river flows south through the town of Mullingar before passing through Lough Ennell, then continues southwest through Kilbeggan — where its current historically powered the mill at the famous Kilbeggan Distillery — and on through Clara, Ballycumber, and Pullough before ultimately joining the River Shannon at Shannon Harbour, north of Banagher. The Brosna is well regarded among fly anglers in the Irish midlands, particularly for its brown trout fishing and the celebrated Croneen trout, a locally distinctive fish that has drawn considerable conservation attention. The river's character varies along its course, offering a range of angling environments across its length.