Lough Neagh, sometimes Loch Neagh, is a freshwater lake in Northern Ireland. It is the largest lake in Northern Ireland, supplying 40% of its water; the biggest on the island of Ireland, the biggest in the United Kingdom, and the biggest in the British Isles.
With an area of 392 square kilometres (151 sq mi), it is the largest lake on the Island of Ireland and the 15th largest freshwater lake within the European Union, and is ranked 31st largest European lake. Located twenty miles (30 km) to the west of Belfast, it is approximately twenty miles (30 km) long and nine miles (15 km) wide. It is very shallow around the margins and the average depth in the main body of the lake is about 9 m (30 ft); although at its deepest the lough is about 25 metres (80 ft) deep.