Originally, the square was called Largo del Mercatello (Market Square). In 1765, it was rechristened Foro Carolina, after the wife of the King of Naples. At that time, the square was modified by architect Luigi Vanvitelli. Modifications included the construction of an ornate semicircular arrangement of columns and statues that now look down on the square. They now mark the western side of a boarding school named for Victor Emanuel II. Vanvitelli, with his changes, essentially converted what had been the rear of a large, pre-existing and ancient monastery into the front of the "new" structure. The western side of the square is flanked by Via Toledo. At the southern side is the church of San Michele Arcangelo. On Via Toledo, in the northern flank of the piazza is the church of Santa Maria di Caravaggio and the Port'Alba, one of the city gates.