A decorated casket in which a A remnant of the body of a saint or a (part of) an object that has been in contact with a saint, Jesus, or Mary. The very first sanctuaries were built on graves of saints. Remnants of these saints were distributed to other churches and chapels. The first altars were usually the sarcophagi of the saints. Hence the custom of placing relics under the altar stone. Relics are also kept in shrines, and sometimes displayed in reliquaries. is preserved.