On the western side of the Square, in Calle di San Nicolò, stands the San Nicolò Auditorium on the periphery of the ancient church of the same name dating back to the early 13th century. Next to it is the attached Augustinian convent, now home to a kindergarten.
Inside, some traces of Giotto-style frescoes are still visible on the walls, further testifying to the antiquity of the building. A detached representation depicting "The Virgin and Child in Glory with Angels" is now preserved at the Civic Museum.
There is also a small belfry, not easily visible from the ground, surrounded by multi-storey houses, with access prominently located inside the building.
The church housed numerous valuable works of art now preserved in other churches and in the diocesan museum. For instance, in the Church of the Holy Trinity, there are two large canvases originating from the church of San Nicolò:
-The Consecration of Saint Nicholas Bishop of Myra (circa 1619) by Pietro Damini;
-The Miracles of Saint Nicholas Bishop of Myra (1618-19) by Andrea Vicentino.
The acoustics for concerts are excellent, and the Auditorium, with its 300 seats, is suitable for hosting conferences and theatrical performances.
