Cavan is the source of many rivers. Shannon Pot on the slopes of Cuilcagh is the source of the River Shannon, the longest river in Ireland at . The River Erne is a major river which rises from Beaghy Lough, two miles (3 km) south of Stradone in Cavan and flows for to Lough Erne. Other rivers in the county include the Blackwater River, which rises near Bailieborough and flows through Lough Ramor, joining the River Boyne at Navan; the Dee which springs near Bailieborough; the River Annalee which flows from Lough Sillan and joins the Erne; and the Cladagh river which rises from Cuilcagh and flows into Fermanagh. The Glyde and the Owenroe also source in Cavan.