Elidir Fawr is a mountain in Snowdonia, north Wales, the northernmost peak in the Glyderau.

Water from this lake flows through huge tunnels into the lower reservoir Llyn Peris.

It is a reasonably short, but steep walk up to the summit, and this can be undertaken from the Deiniolen side or from Nant Peris.

The Deiniolen walk provides views down to Llanberis, while the Nant Peris approach is short and quite steep.

The route makes its way around the headwall of Cwm Dudodyn to Bwlch y Brecan and up to the rocky summit of Elidir Fawr.