Right next to St. Peter's Square is the Borgo district, which retains a medieval appearance. The streets within it are not called "vie" (streets) but "borgo" (village): in fact, the main street, Borgo Pio, connects Via di Porta Castello to Via di Porta Angelica. The street was built by order of Pope Pius IV, who, with a papal bull dated December 5, 1565, entitled "Erectionis civitatis Piae prope arcem Sancti Angeli" ("Erection of the Pious City near the Arch of Saint Angelo"), ordered its construction.

The street is pedestrianized and paved with cobblestones, as are the narrow streets that branch off it. The buildings and shops retain an old-world charm that attracts tourists and Romans alike.
At the corner of Borgo Pio and Vicolo del Campanile stands a graceful Madonnella, a Baroque shrine containing an 18th-century fresco depicting the Virgin and Child.
In the delightful Piazza del Catalone, we find the Fontana dell'Acqua Marcia, whose appearance recalls the shrines that ancient Romans dedicated to pagan gods. The inscription "Acqua Marcia" refers to the water that feeds the fountain; the papal coat of arms is featured in the upper arch.