Bala Lake is a large lake in Gwynedd, Wales. It was the largest natural body of water in Wales prior to the level being raised by Thomas Telford to help support the flow of the Ellesmere Canal. It is 4 miles (6.4 km) long by 1 mile (1.6 km) wide, and is subject to sudden and dangerous floods. The River Dee runs through it and the waters of the lake are famously deep and clear. The town of Bala sits at its northern end and the narrow gauge Bala Lake Railway runs for several kilometres along the lake’s southern shore.
George Borrow wrote of the lake in Wild Wales in 1856, “The lake has certainly not its name, which signifies ‘Lake of Beauty’, for nothing”. In English the lake is named after the nearby town of Bala, whose name means “outlet of a lake” in Welsh. An older, now unused, English name for the lake is Pemble Mere or Pimble Mere.