These vaulted buildings are warehouses from the 3rd Cent AD. Jerome Murphy-O'Connor reports that "the northernmost warehouse was transformed into a Mitraeum by the addition of benches along the sides and an altar at the far end. An off-centre light-shaft near the eastern end of the vault permits a ray of sunlight to fall on the altar at noon on 21 June." It seems to have gone out of use by the 4th Cent.
