Llyn Tegid

The largest natural lake in Wales, Llyn Tegid — also known as Bala Lake — occupies a rift valley in Snowdonia's southern flanks and stretches nearly seven kilometres in length. The lake is notable for containing the gwyniad, a whitefish species found nowhere else in the world, which evolved in isolation since the last Ice Age. The Bala Lake Railway, a narrow-gauge line, follows the southeastern shore and provides views across the water to the Aran mountains.