Garreg Las [Twyn-Swnd]

Rising above the wild, western moorland of the Mynydd Du, this limestone-crowned Hewitt offers a rugged sense of isolation rarely found elsewhere in the Brecon Beacons. The broad plateau is dominated by two massive prehistoric cairns, providing a stark silhouette against expansive views of Fan Brycheiniog and the Usk Valley.

• •The name Garreg Las translates from Welsh as 'Blue Stone' or 'Grey Stone'. In older Welsh, 'glas' described a color spectrum including blue, green, and grey; here it refers to the weathered limestone outcrops and gritstone boulders that litter the summit.
• •The summit area is also known as Twyn-Swnd, which translates as 'sand mound'. This refers to the gritstone debris and sand found around the prehistoric burial sites, contrasting with the surrounding peat moorland.
• •The two massive Bronze Age cairns on the plateau are among the most impressive in South Wales. Their size and prominent location suggest this high ridge was a site of significant ritual importance for communities living in the valleys below thousands of years ago.
• •The hill marks a historic frontier, sitting directly on the boundary between the traditional counties of Carmarthenshire and Brecknockshire.
• •From the summit, walkers can look directly east across the glacial cwm to the dramatic, sky-lined escarpment of Fan Hir and the high peaks of the Black Mountain range.
• •While the name promises a 'Blue Stone', the primary color palette on a typical afternoon here is a very determined, horizontal shade of rain-cloud grey.