During work on the sewer system close to Jerusalem’s Damascus Gate, a mosaic floor from the Byzantine Era was uncovered at a depth of just one meter. The mosaic, which measures 45 by 32 inches (114 by 80 cm), is almost completely preserved. It was made around 550 AD.

The leader of the excavation, David Gellman, talks of an archaeological miracle: “The mosaic was probably part of a hostel for pilgrims. The inscription mentions Emperor Justinian and a priest called Konstantin, the founder of the building. Konstantin was the abbot of the Nea Church, which when it was completed in the year 543 was the largest church in Jerusalem.

Already by this time, Jews and Christians were making pilgrimages to...