In the heart of Montalto’s historic center, initially named Piazza Felice in honor of the townsman Felice Peretti (later Pope Sisto V), it was renamed Piazza Umberto I following the assassination of the King in 1900 at the Royal Villa of Monza. The square is lined with the main palaces and buildings that bear witness to the glorious past of the Sistine Presidium: the Governor’s Palace, historically the seat of the Presidium and later the Town Hall; the Baroque Church of San Nicolò; the houses of Sisto V and Giuseppe Sacconi; and, on the opposite side, the Civic Tower Palace, formerly the Palazzo dei Priori.