Lough Neagh is a large freshwater lake in Northern Ireland. It is the largest lake by area in the British Isles, with a surface area of 392km2. It supplies 40% of Northern Ireland's water. Its main inflows are the Upper River Bann and River Blackwater, and its main outflow is the Lower River Bann. Its name comes . The lough is owned by the Earl of Shaftesbury.