River Bandon, river in County Cork, Ireland, flowing in a valley cut in rocks of the Carboniferous Period (about 360 to 300 million years ago) but covered with glacial drift and alluvium. The river rises in the Maughanaclea Hills in western Cork and flows east to a point west of Caha Bridge where it turns south, before turning east again to the southeast of Dunmanway. It then flows in a broad fertile valley, with woodlands, to Bandon, and loops in an arc past Inishannon, where it flows southeast and then east, becoming an estuary reaching the sea in Kinsale Harbour, a distance of about 40 miles (64 km). The Bandon Estuary in the vicinity of the town of Kinsale is an important resort and fishing area.