Basilica of San Clemente

This guide to the Basilica of San Clemente in Rome follows Irish Dominican friar Joseph Mullooly, who in 1857 acted on a hunch and began digging beneath the church he served. It traces the buried fourth-century basilica he found first, with frescoed walls and the tomb of Saint Cyril, missionary to the Slavs, before reaching a Roman-era structure sealed even further down. That deepest chamber was built for a mystery cult devoted to the god Mithras, centuries before Christianity arrived on this spot.