Bala Lake

Bala Lake is a large freshwater glacial lake in Gwynedd, Wales. The River Dee, which has its source on the slopes of Dduallt in the mountains of Snowdonia, feeds the 3.7 miles long by 0.5 miles wide lake. It was the largest natural body of water in Wales before its level was raised by Thomas Telford to provide water for the Ellesmere Canal.

The town of Bala, which was once an important centre for the North Wales woollen trade, is located on the north-eastern end of the lake. The 3-mile narrow gauge Bala Lake Railway, between the town and Llanuwchllyn, runs along the lake's south-eastern shore using a section of former trackbed from the former Ruabon–Barmouth line.

Source: Wikipedia