County Offaly population. It is the largest county by area and the third largest by population in the Midlands. Lusmagh Tullamore is the county town and largest town in Offaly and is the 30th largest in Ireland. Offaly borders seven counties: Galway, Roscommon, Tipperary, Laois, Westmeath, Kildare and Meath. The Slieve Bloom Mountains are in the southern part of the county on the border with County Laois. Offaly has the 24th highest county peak in Ireland. The highest point is Arderin () in the Slieve Blooms at . The Slieve Bloom Mountains contain the county's highest points including Stillbrook Hill and Wolftrap
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