Which Northern Irish lough is the largest lake in the British Isles?

Lough Neagh is Northern Ireland’s largest lake and the largest lake in the British Isles by surface area. It covers about 383 square kilometers and lies roughly 20 miles west of Belfast.

The lough is broad but surprisingly shallow: its average depth is about 30 feet, while its deepest point is around 80 feet. Several rivers feed it, including the Upper Bann, Blackwater, Main, and Moyola; its principal outlet is the Lower Bann, which flows north toward the sea. The catchment spans Northern Ireland and a smaller portion of the Republic of Ireland.

Lough Neagh is more than a geographic record-holder. It supplies roughly 40.7 percent of Northern Ireland’s drinking water and supports fisheries, wetlands, birds, and local communities. “Lough” is simply the regional term for a lake. Loch Lomond is a common wrong answer because it is Britain’s largest lake by some alternative measures, while Lough Neagh is the largest by area across the British Isles.