Llyn Cwmffynnon lies about half a mile east of Pen-y-Pass in Snowdonia. While most visitors will be heading west from this location to climb Snowdon, hardly any head in the opposite direction. The lake is set in moorland, and access is by a signposted public footpath from Pen-y-Pass. An alternative route begins at a layby on the A4086 just east of the Pen-y-Gwryd Hotel, and follows the Nant Gwryd up to the lake. Parking is in laybys on the A4086. The Nant Gwryd forms the county boundary between Gwynedd and Conwy, and passes under the road about 200 yards east of the Pen-y-Gwryd Hotel. Parking is P&D on the Gwynedd (west) side and free on the Conwy (east) side.
