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 Llithrig y Wrach Pen Llithrig y Wrach Pen Llithrig y Wrach is a mountain peak in Snowdonia, North Wales. It is one of the four Marilyns that make up the Carneddau range. To the east is Creigiau Gleision, another Marilyn, while to the west is Pen yr Helgi Du and Carnedd Llewelyn. Craig Eigiau and Llyn Eigiau can be seen to the north, while Gallt yr Ogof, Glyder Fach and Tryfan can be viewed to the south. It has one of the more colourful names of any British mountain, translating as "slippery peak of the witch", perhaps in reference to the boggy conditions