Llyn Cwm Llwch both Pen y Fan and Corn Du and indeed from the spur of Pen Milan to its west. Llyn Cwm Llwch Llyn Cwm Llwch () is a small lake or pool in the Brecon Beacons National Park in Powys, Wales. It is between 1 and 2 acres: much smaller than the two glacial lakes in the west of the Black Mountain (range): Llyn y Fan Fawr and Llyn y Fan Fach. It is of glacial origin, occupying a rock hollow beneath the peaks of Pen y Fan and Corn Du in the central Brecon Beacons. It is drained by the
Pen-y-Pass Pen-y-Pass Pen-y-Pass is a mountain pass in Snowdonia, Gwynedd, north-west Wales. It is a popular location from which to walk up Snowdon, as three of the popular routes (the Miners Track, the Pyg Track and the ascent via Crib Goch) can be started here. Glyder Fawr, to the north, is also accessible from here. Situated at the high point of the Llanberis Pass at an altitude of , the road was built in the 1830s to allow ore from the mines on Snowdon to be transported to Llanberis. It would be taken down the Miners Track to a store-house at