Borgo, Rome: Castel Sant'Angelo, the Leonine City and the Quarter That Was Demolished

Until 1936 a wedge of houses called the spina stood between two streets, Borgo Vecchio and Borgo Nuovo, running from the Tiber towards St Peter's. Borgo Vecchio replaced the collapsed medieval Portica — Italian Wikipedia cites its near-constant width of 6.90 metres as the evidence — and Borgo Nuovo was the Via Alexandrina, opened by Alexander VI for the Jubilee of 1500. Demolition began ceremonially on 29 October 1936 at 09.00, when Mussolini struck the cornice of Palazzo Sauve in piazza Pia with a pickaxe, accompanied by the governor Giuseppe Bottai; the project had been shown to Mussolini at Castel Sant'Angelo on 20 June 1936 and to Pius XI in the Loggia di Raffaello eight days later. Expropriations ran under Regio Decreto 981 of 1931, and the named contractors were Vaselli, La Prenestina, Tudini e Talenti, Federici and Manfredi. By 8 October 1937 the spina had ceased to exist and St Peter's was visible from Castel Sant'Angelo. Most of the displaced residents were moved to the borgate, among them Acilia, and no survey of the old quarter was ever made — only drawings. Piazza Scossacavalli, the square at the centre of the spina, went in 1937; its fountain by Carlo Maderno was re-erected in front of Sant'Andrea della Valle, in rione Sant'Eustachio, where it still stands. So did San Giacomo a Scossacavalli in 1937, the Oratorio di San Filippo Neri in Borgo in 1938, San Michele Arcangelo ai Corridori and the Ospedale di San Carlo in 1939, Santa Maria della Purità between 1937 and 1940, and Sangallo's Palazzo del Governatore di Borgo in 1936–37. None was rebuilt. Older losses lie under the same ground: the Meta Romuli, a pyramidal Roman tomb in the Ager Vaticanus, was demolished in 1499, and the round tomb beside it known as the Terebinto di Nerone had gone from the seventh century. This account is Italian Wikipedia's, citing Vannelli, Parisi Presicce and Petacco, the Archivio Centrale dello Stato, Ceccarelli and Borgatti.

Borgo runs up to the border of Vatican City, and the border is where this guide stops. St Peter's Basilica, St Peter's Square, the Vatican Museums and the Sistine Chapel are inside a sovereign state; they belong to no rione and none of them appears here. St Peter's Square is Vatican territory under Article 3 of the Lateran Treaty, and the Italian policing carried out there is a concession on foreign soil rather than evidence of Italian territory. Where the line actually runs, this guide will not say. The Treaty fixes it only by an annexed map at 1:5000, with no verbal description at all; the border commission of 1932–33 never had its conclusions ratified; and the paving detail commonly described as marking the boundary is not something this corpus publishes as fact. Between the two states there is a third legal tier that a visitor walks through without noticing. Under Article 15 of the Treaty, a list of named properties standing on Italian soil — several of them on and around via della Conciliazione — carry the immunities that international law grants to the headquarters of diplomatic agents. They are not Vatican territory and they are not foreign soil; anyone visiting them is subject to Italian law. The Holy See states that its extraterritorial properties in Rome, the Seminario Romano Minore excepted, are named in the Holy See's own enumeration, following the Holy See's 1982 accession to the 1972 World Heritage Convention. One thing you may expect to find here and will not: the Campo Santo Teutonico, which this guide does not carry. Nothing about the Leonine wall here should be read as marking that border either: Leo IV walled the quarter between 848 and 852 after the Saracen sack of 846, with Lothar I decreeing and part-financing the work in October 846, and Paul III and Pius IV extended it to 1565 — but most of the surviving circuit is now the Vatican's own perimeter, and only the stretch standing in Borgo belongs to this guide.

Borgo has no metro station inside it. Italian Wikipedia's article on the rione names the Ottaviano station, on metro Line A, as its metro link; the station stands beyond the rione boundary, in Prati. OpenStreetMap's rione and quartiere polygons put Roma San Pietro railway station outside Borgo as well, in Quartiere XIII Aurelio. On the ground the rione has two spines. Via della Conciliazione is the one every visitor uses: about 420 metres of sampietrini between Largo Giovanni XXIII, at the Tiber end, and Piazza Pio XII at the Vatican end, CAP 00193. Under the Janiculum, the Galleria Principe Amedeo di Savoia-Aosta carries road traffic through a single bore of 0.250 km to its portal at Porta Santo Spirito; motorcycles under 125 cc are excluded from it. To steer by, Roma Capitale gives Castel Sant'Angelo's address as Lungotevere Castello 50, and the parish of Santa Maria in Traspontina gives its own visitor entrance as via della Conciliazione 14. This guide publishes no walking times and no distance it has not taken from a source, so work the geography out from the street numbers rather than from an impression.