New homes for sale in Ystradgynlais, between Swansea and the beautiful Brecon Beacons National Park. Our new two, three, and four-bedroom homes at Maes Y Rhos are served by a direct route to Swansea, just 15 miles away. From Abercraf, just 2.5 miles away, you can step over the border of the National Park and set your sights on Pen y Fan, the highest point of this famous 350 square-mile expanse of countryside.