ISTANBUL, TURKEY—Hurriyet Daily News reports that researchers from Istanbul Municipality’s Cultural Heritage Department discovered a 1,500-year-old tunnel while exploring the remains of Saint Polyeuktos Church, which was built between A.D. 524 and 527 and stood until about the eleventh century. The passageway was lined with marble and decorated with reliefs. A 1,900-year-old Roman statue, bronze coins, stamped bricks, marble fragments, pottery, oil lamps, and glass and metal artifacts have also been uncovered during the recent excavations. To read about a submerged church found 100 miles from Istanbul, go to "Sunken Byzantine Basilica," one of ARCHAEOLOGY's Top 10 Discoveries of 2014.