Chiesa di San Giovanni alle Quattro Facce

San Giovanni alle Quattro Facce was a rectangular structure measuring roughly 20 meters long and 12 meters wide, with three aisles accessed through three separate doors. The building stood at the intersection of modern Via Arrigo Boito and Piazza Giordano dell'Amore until demolition in 1786.

The church rose from the foundations of a Roman temple dedicated to Janus Quadrifrons, a four-faced deity. Architect Francesco Maria Richini carried out a complete reconstruction in the 17th century that shaped how this building was understood until its demolition.

The church embodies Milan's shift from pagan worship to Christian faith through its transformation of an existing temple. People could witness at this location how layers of religious belief occupied the same sacred space over time.

The building was accessible on foot via central Milan streets, positioned prominently at an intersection where people naturally gathered. Today visitors can only locate where it stood by examining how the surrounding streets are laid out.

The church's name directly referenced the four sides of the original Roman temple, preserving in its title the memory of what came before. This naming choice kept the building's pagan foundation present in how people spoke of it long after conversion to Christian use.