Most of Longford lies in the basin of the River Shannon with Lough Ree forming much of the county's western boundary. The north-eastern part of the county, however, drains towards the River Erne and Lough Gowna. Lakeland, bogland, pastureland, and wetland typify Longford's generally low-lying landscapes: the highest point of the county is in the north-west - Carn Clonhugh (also known as Cairn Hill) near Drumlish at 279 m (916 feet). Cairn Hill is the site of a television transmitter broadcasting to much of the Irish midlands.