What's the noun for sacraries? Here's the word you're looking for.
sacrarium
(historical) In Ancient Rome, a place where sacred objects were kept, either in a temple (the adytum) or in a house (holding the penates)
The area surrounding the altar of a Christianchurch; the sanctuary or piscina. Sometimes specifically a drain directly to the earth, perhaps including reference to a basin, for washing vessels from consecration.