Two entries with the name Perilous Chapel.
Perilous Chapel
A chapel visited by Gawain and Hector during the Grail Quest.
Both knights saw visions portending the completion of the quest by Galahad, Perceval, and Bors. The visions signified the unworthiness of both Gawain and Hector.
Source
Post-Vulgate Queste del Saint Graal | 1230-1240
Perilous Chapel
The chapel in the Perilous Cemetery, found in Perlesvaus and Malory’s Le Morte Darthur. It would appear to have been in one of the Perilous Forests.
In the former, Perceval had to brave the horrors of the haunted cemetery and chapel to retrieve the shroud which had covered Jesus Christ. Perceval’s sister, Dandrane, also had to journey to the Perilous Chapel to retrieve a piece of the shroud. Finally, Lancelot was required to face the Perilous Chapel to obtain a sword and cloth in order to heal Meliot de Logres.
It is the latter knight’s adventure that Malory embellishes. In Le Morte Darthur, the Perilous Chapel is heavily guarded, and is ruled by Hellawes the Sorceress, lady of the Castle Nygramous. When Sir Meliot de Logres killed Sir Gylbert the Bastard, Gylbert’s lover, a witch, cast a spell on Sir Meliot so that his wounds would never be healed unless some knight braved the Perilous Chapel and retrieved a bloody sword within. Lancelot came upon the sickly Meliot and promised to help him.
Riding in a deep forest, Lancelot followed a black brachet which was tracking a feute of blood. The brachet led him over an old, feeble bridge into an old manor, where he found the body of Sir Gylbert the Bastard, with his wife grieveing for him. Leaving the manor, Lancelot met a damsel he knew, who told him that her brother, Sir Meliot de Logres, had fought and killed Sir Gylbert that day, but had been wounded himself. (In Le Morte Darthur, Gylbert’s lover, a witch, cast a spell on Sir Meliot so that his wounds would never be healed unless some knight braved the Perilous Chapel and retrieved a bloody sword within.) The bleeding could not be staunched, and Meliot could only be saved if his wounds were searched with the sword and a piece of the bloody cloth wrapping the dead knight in the Chapel Perilous.
Lancelot proceeded to Chapel Perilous, on the front of which he saw many fair, rich shields hanging upside-down. Thirty armed knights, twice the size of any man, barred his way, grinning and gnashing their teeth at him; when he resolutely stepped forward, holding his shield before him, and pushed through the ranks of knights, they stood aside and let him pass. In the chapel, by the light of a single dim lamp, he found the body of Sir Gylbert the Bastard lying covered by a cloth of silk. When Lancelot cut off a little of the cloth, the earh seemed to quake. He also required the dead knight’s sword. When he came back outside, the thirty knights, in unison, threatened him to death if he did not lay down Sir Gylbert’s sword. Again, Lancelot passed resolutely and safely through their midst.
It turned out that the entire Chapel was an elaborate charade created by Hellawes the Sorceress, and Lancelot was the first person to call her bluff. Hellawes appeared before Lancelot, at first threatening him to his death if he did not lay down the sword, then tried to get him to kiss her once. When he refused, she confessed that either to lay down the sword or to kiss her would have cost him his life. She had been in love with him for seven years and, despairing of his love, had hoped to have his dead body to kiss and fondle. Lancelot left and went back to Meliot to cure him. Hellawes died within a fortnight from sorrow.
Sources
Perlesvaus | Early 13th century
Le Morte Darthur | Sir Thomas Malory, 1469-1470