The stretch of fortification between Porta Latina and Porta San Paolo is about 2.6 km long. It is distinguished by the presence of an imposing Renaissance restoration known as the Bastione Ardeatino, which fortified and replaced an extensive stretch of wall.
From Porta Latina to Porta San Sebastiano, the route is rather varied, with a fairly sharp change of direction at Via Talamone. After Porta San Sebastiano however, it is almost straight, descending as far as Porta San Paolo.
The walls show a sharp break at Via Cristoforo Colombo, whose archways, opened for vehicular traffic in the 1950s, interrupt the continuity of the layout and the urban fabric. A similar renovation led to the opening of the passageway on Via Guerrieri, where the Honorian-era masonry, Renaissance and 1960s restorations are clearly visible. The section that joined the walls of Viale Giotto to Porta Ostiense was opened to allow the road to pass from Viale di Porta Ardeatina to the piazza behind Porta San Paolo.
Along the entire section outside the city, from Viale di Porta Latina to Via di Porta Ardeatina, the walk is pleasant and the view of the walls always enjoyable.
On the outside, the first section is flanked by neighbourhoods that grew up during the 20th century: these are housing blocks which, proceeding south-westwards, become first residential and then high-end starting from the intersection with Via Appia Antica.
Beyond Via Cristoforo Colombo, proceeding towards Via Guerrieri, the urban fabric is distinguished by the presence of the Villa Osio park. Beyond this park is a district built in the second half of the 20th century.
Inside the city, from Porta Latina to Largo Giovanni Chiarini, is a series of large private properties obstructing the road network and hindering the visibility of the Walls. On the other hand, the section that runs along Viale Giotto and borders the San Saba district is accessible.
The section of the Walls along the Viale di Porta Ardeatina is one of the best preserved and most important examples of the architectural type used in the reconstruction of the defensive walls at the time of Honorius. The covered walkway on these walls can be seen on the interior elevation, whereas the section along Viale Giotto is uncovered.
On the exterior face, the brick curtain walls associated with the works carried out by Honorius are largely preserved along the entire stretch, while the Aurelian masonry can be best appreciated in the stretch in front of Villa Osio. There are some interesting embrasures for archers in the walls, some of which were altered in the 19th century to be adapted to firearms. There are also numerous and consistent reconstructions by the popes, from the Middle Ages to the second half of the 19th century, which can be dated thanks to numerous coats of arms and papal inscriptions.
