What is "glaslyn"

Glaslyn is a lake in the Snowdonia National Park in Gwynedd, north-west Wales.

It is found at approximately above sea level in a cwm on the eastern flanks of Snowdon. It is a rough ellipse in shape, about east–west and about north–south, and the Miners' Track runs along the northern shore.

Glaslyn is the source of the Afon Glaslyn, the major river of Gwynedd, which runs east to the reservoir of Llyn Llydaw before turning south-west to reach the sea at Porthmadog.