On the surface, the Chiesa di San Filippo Apostolo (Church of Saint Philip the Apostle) looks like most any other cathedral from the 1700s. The scale is grand, the paintings venerating Christ's life are dramatic, and carvings of the Mother Mary portray blissful serenity. This is where the similarity ends.

This Sicilian church was built on the remains of a medieval synagogue, and all that's left of the synagogue now sits deep under the church, three levels below: a perfectly preserved mikvah. This Jewish ritual bath was used by women for purification ritual before marriage, after childbirth, and then after every menstrual period, until the Inquisition drove the Jews out of Sicily in 1492.

A name, Asher, is etched in Hebrew on the limestone wall. It's thought to be the name of the man who built this underground bath, which taps into a clean and clear (and cold) underground spring. There are three steps leading into the bath, three being a kabbalistic symbol of the harmony that comes about by embracing opposites. The mikvah is 18 meters (60 feet) below street level, 18 representing the symbol for chai, the will of God. 

For World War II history buffs, the second underground level beneath the church will be of interest. This tunnel network was originally used by the Greeks as a water system and later was used as a massive bomb shelter. There are tunnels and passages running all under the island of Ortigia, from San Giuseppe Square to the sea. These cavernous spaces protected over 10,000 citizens of Syracuse during the Allied bombing. You can still see graffiti depicting images of British planes and parachutes described in Sicilian.

Moving up to the first underground level, there are Stations of the Cross frescoes, and memento mori paid for by the wealthy congregates, who lie buried in church crypts.