 Pwll y wrach

Pwll y wrach or Pwll-y-wrach (Welsh for "pool of the witch") is a feature on the River Ennig near Talgarth in south Powys, Wales.The river plunges in two separate streams over a lip of hard rock (the Bishops Frome Limestone, formerly known as the Psammosteus Limestone) into a pool scoured in the softer mudstones of the underlying Raglan Mudstone formation.