crypt (krĭpt) [key] [Gr., = hidden], vault or chamber beneath the main level of a church, used as a meeting place or burial place. It undoubtedly developed from the catacombs used by early Christians as places of worship. Early churches were commonly built over the tombs of martyrs. Such vaults, located beneath the main altar, developed into the extensive crypts of the Middle Ages that in many churches of the 11th and 12th cent. occupied the entire space beneath the sanctuary. At Canterbury the 12th-century crypt forms a large and complete lower church in itself. The crypt of the Rochester Cathedral is partly above ground. The cathedrals at Chartres and at Bourges have crypts typical of the Gothic development.