Llyn Cowlyd, Snowdonia National Park

Llyn Cowlyd is the deepest lake in northern Wales. It lies in the Snowdonia National Park at the upper end of Cwm Cowlyd on the south-eastern edge of the Carneddau range of mountains, at a height of 1,164 feet above sea level. The lake is long and narrow, measuring nearly 2 miles long and about a third of a mile wide, and covers an area of 269 acres. It has a mean depth of 109 feet and at its deepest has given soundings of 229 feet, this being some 45 ft greater than its natural depth, the water surface having been raised twice by the building of dams. ()