The Cafe Gambrinus is not the only thing on the Piazza Trieste e Trento. At the far end is the Chiesa di San Ferdinando. Originally built as a Jesuits church in 1636, in 1767 it was granted to another order who dedicated it to Saint Ferdinand III of Castile. Ferdinand had ruled Casteel between 1217 and 1252, and was canonised in 1671.
Beyond that I don't have a lot of information about the place for you. One thing is for certain, Italy is not short of churches.