SOFIA, BULGARIA—Archaeology in Bulgaria reports that researchers led by Ivan Hristov of Bulgaria’s National Museum of History discovered a Thracian fortress in the Black Sea, on currently submerged land that once connected St. Thomas Island to what is now Bulgaria. Last year, the team conducted a survey of the three-acre island and found a Thracian settlement with ritual pits, an early Byzantine settlement, and a monastery dating to the Late Middle Ages. The researchers suggest the island’s location—on the sea and right off the ancient road from Apollonia Pontica to Byzantium—made it prime real estate. To read about a recent discovery in Bulgaria dating to the Roman period, go to “Mirror, Mirror.”