Eldah face eldah big via Dinorwic quarry

The Dinorwic quarry (; Welsh: [dɪˈnɔrwɪɡ]; also known as Dinorwig quarry) is a large former slate quarry, now home to the Welsh National Slate Museum, located between the villages of Llanberis and Dinorwig in North Wales. It was the second largest slate quarry in Wales, indeed in the world, after the neighbouring Penrhyn quarry near Bethesda.

Elidir Fawr is a mountain in Snowdonia, north Wales, the northernmost peak in the Glyderau. To the north of the summit is a small lake, Marchlyn Mawr, which is the upper reservoir for Dinorwig power station, a pump-storage power station hidden inside the mountain. Water from this lake flows through huge tunnels into the lower reservoir Llyn Peris.