The River Honddu (Afon Honddu) runs through the Black Mountains in the Brecon Beacons starting in Llanthony Valley and said, according to folklore, to be the home of a small grey Ceffyl-dwr (a welsh water horse similar to a Kelpie).
At the head of the Vale is the Gospel Pass, which is reputed to have been named after the time in the 12th century when the Third Crusade passed through the area preaching and fund raising. Nearby, at Capel-y-ffin, is an 18th-century church or chapel, one of the smallest in the country, and close to the former home of designer Eric Gill. Further south near the valley entrance, at Cwmyoy, the church there has suffered gradual subsidence over the centuries, and is best known for the disorienting tilts and twists of the building which add to its character. A few miles away, further into the Black Mountains, is Partrishow or Patricio, which has an outstanding 11th-century church.