Dating back to 1100 BC, it’s riddled with natural and manmade caves, and served as a temple for Aphrodite and then was taken over by monks who lived in tiny caves. Many stone steps carved by monks are still visible in Baptistry church in Patmos, as well as natural reservoirs that collected rainwater and manmade niches for candles and other religious and votive offerings. Look for submerged ruins of a church nearby.