The Catacombs of Milos, on the hillside near the village of Trypiti, are the only surviving Christian catacombs in Greece. Cut into the soft volcanic rock in the 1st through 5th centuries AD, the network of tunnels contains over 2,000 burial niches carved directly into the walls — arched recesses where the dead were laid on stone shelves and sealed with tiles or slabs. The tunnels are cool even in the height of summer and the rock has a soft, carved quality that makes the space feel intimate rather than monumental.
Entry is by guided tour only, with groups taken through the main accessible passages by local guides. The tours are short but informative, covering both the geology of the site and the history of the early Christian community on the island. The catacombs sit just below the ancient theatre and the Venus de Milo discovery site, so the three can be combined comfortably in a morning. Opening hours are reduced outside the main summer season, and the site closes on Mondays.