One of the most fascinating tourist sites in Jerusalem is a building that stands atop Mount Zion, the southwest hill of Old Jerusalem. The lower story of this unique building is traditionally identified as the Tomb of David and the upper story as the room of Jesus’ Last Supper. What is the historical evidence for these claims? How likely is it that these sacred sites are actually located on Mount Zion, let alone in this specific building? Can archaeology help answer these questions?