Grid Ref: SN809203 Access: There are 1,852km of public rights of way in the Park, allowing visitors to explore the area on foot, on horseback or by bicycle. There are also guided walks and events organised by Park Rangers. Website: www.breconbeacons.org

The Brecon Beacons is one of Wales' three National Parks, running from Hay on Wye in the east to Llandeilo in the west and covering an area of 519 square miles.

The Black Mountains, the Central Beacons and Fforest Fawr are all part of the National Park which includes moorland, forest, valleys, waterfalls, lakes, caves and gorges.

Around 60% of the area is made up of great blocks of old red sandstone and along the A4069 between Brynaman & Llangadog, evidence of the earliest vascular plants can be seen in the sandstone.

The geology in the southern part of the park changes to outcrops of limestone and pennant sandstone.

Craig Llyn and other craigs along the road that runs down the Rhondda are made up of pennant sandstone which was formed when vast quantities of sand eroded off the rising mountains to the south were dumped in South Wales. The area lies immediately above the coal levels, which were formed when the trees rotted beneath their covering of sand.