During the early centuries, the Monastery of St. John was under constant threat by several enemies including the Crusaders, the Arabs, the Turks and pirates. All of them coveted the monastery’s treasures. As the town of Chora grew and encircled the monastery, the residents relied on sentinels to constantly scan the horizon for potential intruders. At the first sign of danger, the monks rang the bells on The Terrace. This notified the Patmians to immediately seek refuge within the formidable monastery walls.