Llyn Padarn is a glacial lake in Snowdonia, Gwynedd region of Wales. It is long about 3.2 km (2 miles) and its depth reaches 29 m (94 feet), being considered as the sixth deepest lake in Wales. This lake is one three remaining natural localities to support the rare alpine fish, Arctic Char. Otters and small numbers of wildfowl habituate the lake. It is connected to the Llyn Peris in the south-eastern part. A remarkable feature of the area is Coed Dinorwig, a rare and ancient woodland.