Ynyscedwyn Ironworks Park was created on the site of the ironworks which made Ystradgynlais famous. According to evidence found here, iron was being smelted here from as early as 1612. The most important period for these works was during the early nineteenth century where the hot blast method was invented here. Iron making ceased in 1941, and these soaring arches and preserved machinery are all that now remain. The pastoral landscape, overlooked by craggy hills, offers visitors peaceful respite and the opportunity to witness a rich and unique heritage hundreds of years in the making.