A graveyard and church, so named because it contained the bodies of Galahad, a son of Joseph of Arimathea, and Simeon, a follower.
In the Knight of the Cart episode from the Vulgate Lancelot, Lancelot raises the stone on Galahad’s tomb, proving that he has the mettle to rescue Guinevere from Meleagant (Meleagaunce). Lancelot failed to raise Simeon’s tombstone – an adventure completed by his son Sir Galahad during the Grail Quest.
Source
Vulgate Lancelot | 1215-1230