In the Post-Vulgate, a castle in the Forest of Darnantes where Simeon, a sinful follower of Joseph of Arimathea, was forced to burn until Galahad came and freed him of his torment.
Elsewhere, the Perilous Palace is named as the castle of Pellehan, the Grail King, which is usually called the Palace of Adventures.
Sources
Post-Vulgate Suite du Merlin | 1230-1240
Post-Vulgate Queste del Saint Graal | 1230-1240
