Picws Du falls within Fforest Fawr Geopark and its prominent summit is marked by a large Bronze Age round barrow at a height of 2457 feet above sea level. Waun Lefrith is the other, lower summit of the Bannau Sir Gaer / Carmarthen Fans situated to the west. The peak overlooks the glacial lake of Llyn y Fan Fach in the cwm below. As the peak sits on the edge of the escarpment on a ridge which juts out into the valley below, the views from the summit are panoramic and extensive. The views to the north are especially impressive when the weather is clear, looking towards the Cambrian Mountains, Mynydd Epynt and Brecon. Swansea and the Bristol Channel can just be seen on the horizon to the south, across the gently falling dip slope. Pen y Fan and Corn Du are distinctive landmarks seen directly to the east across Fforest Fawr.