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 Fan held the ashes or other remnants of a dead person or persons since multiple burials together are common in the British Bronze Age. It also held grave goods left with the human remains, such as flint tools, cinerary urns, or flower tributes. The similar round barrow on Fan Foel was excavated in 2002-4 and revealed such items in the central cist, the flowers being those of meadowsweet. The name "Pen y Fan" consists of the Welsh words "pen" ('top, head, peak, summit', etc.), "y" ('the') and "fan", a mutated form of "ban" ('summit, crest, peak, beacon, hill, mountain', etc.). The