Coordinates: 51°56′13″N 3°19′16″W / 51.937°N 3.321°W
Fforest Fawr Geopark was the first Geopark to be designated in Wales having gained membership of both the European Geoparks Network and the UNESCO-assisted Global Network of National Geoparks in October 2005. The Geopark aims to promote and support sustainable tourism and other opportunities to improve the economy of the area whilst safeguarding the natural environment. Its aims largely coincide with the statutory duties and purpose of the National Park within which it sits.
The Geopark comprises the western half the Brecon Beacons National Park in southern Wales. At its heart are the mountain massifs of Fforest Fawr, the Black Mountain (Welsh: 'Y Mynydd Du') and the central Brecon Beacons. The designated area includes the surrounding lowlands; principally parts of the Usk, Towy, Tawe and Taf valleys.
Rocks from the Ordovician Period through to the Carboniferous outcrop in various parts of the Geopark. The oldest (of late Ordovician age) occur in the northwest whilst the youngest (of late Carboniferous age) occur along its southern margins.