Cut into the rock below the parish church, the sanctuary is one of the oldest places of Christian worship on Malta. A flight of steps takes you down into a small whitewashed chapel built into a natural cave; the focal point is a Byzantine-style fresco of the Madonna and Child, blackened by centuries of candle smoke and surrounded by hundreds of ex-voto offerings — silver hearts, model boats, tiny limbs in wax — left by pilgrims giving thanks for prayers answered.
It is still actively used. Maltese families come here from across the island to christen their children. Outside school holidays and the September feast it is usually quiet and the keepers are happy to explain what you are looking at. There is no fee but donations are welcome.