Brecon Beacons, Waterfall Country

Felicity Evans visits the waterfalls and swallow holes at the western end of the Brecon Beacons, and discovers that besides its natural beauty, it's an area with a rich industrial heritage. Today its deep, mossy ravines are of great interest to walkers and potholers. But the waterfalls, Felicity discovers, gave rise to local industries - including a gunpowder works, and the silica mines provided firebricks that were shipped around the world.

She even walks behind one of the waterfalls, Sgwd Y Eira, the waterfall of snow.

Producer: Mark Smalley.