The Arch of Sixtus V can be found on the Largo Sisto V, where the rione Castro Pretorio meets the quartiere Tiburtino in Rome. The gate can be considered the entrance to the San Lorenzo neighbourhood, which is not an official district (rione), but a local name for part of the Tiburtino district.
Arch of Sixtus V Rome
History and description

The arch itself is a continuation of the Acqua Felice aqueduct and is also called the Arch of the Pears, because of its adornments, the pear being part of the coat of arms of Pope Sixtus V Peretti.
The Arch of Sixtus V has three openings and consists of big blocks of the tuff stone called peperino with travertine marble decorations. On both sides of the arch symbols associated with Pope Sixtus and his family can be seen, such as the star, the mountains and the lion.
The lower inscription on the Piazzale Sisto V side shows the date of its construction “In the Year of the Lord 1585 the first year of his pontificate”, while the one above it says that Sixtus V, out of his own pockets, paid for the creation of 13 miles underground and 7 miles on arched constructions, of the Felice Aqueduct.
The inscription on the San Lorenzo side boasts that Sixtus, also with his own money, had the two roads, both in length and in width, constructed that lead to the churches of Saint Mary Major and Saint Mary of the Angels and Martyrs, in order to encourage the people’s devotion.