Marchlyn Mawr reservoir is a high level lake in Snowdonia behind Elidir Fawr mountain. It is used as the high level water source for Dinorwig power station, a pump storage hydroelectricity scheme.

It is said that nearby lies the cave containing Arthur's treasure, a source of dazzlement to the wanderer who sees it, and of disaster to the pilferer who touches it.

External links

• www.geograph.co.uk : photos of Marchlyn Mawr and surrounding area