County Offaly County Offaly County Offaly () is a county in Ireland. It is part of the Midlands Region and is also located in the province of Leinster. It is named after the ancient Kingdom of Uí Failghe and was formerly known as King's County. Offaly County Council is the local authority for the county. The population of the county is 78,003 according to the 2016 census. Offaly is the 18th largest of Ireland's 32 counties by area and the 24th largest in terms of population. It is the fifth largest of Leinster's 12 counties by size and the 10th largest by
County Offaly Mountain which are the county's second and third highest peaks. Croghan Hill rises from the Bog of Allen and is located in northern Offaly. Although only 234 metres high, it is known for its view over the surrounding area and it stands out by itself. The floodplain of the River Shannon is in the north-western part of the county. The River Camcor runs through the town of Birr and is a Wild Trout Conservation Area. The River Brosna runs across the county from Lough Owel in Westmeath to Shannon Harbour. Silver River runs through several towns in the south of