The Mura Farnesiane is the defensive wall founded in the 16th century that enclosed the city. Walking along Via XXI Aprile you can see a long stretch of this wall, together with the surrounding ditch that now hosts sport and music events. 

It is also very relaxing to take a walk along Via Maculani, which runs close to the wall on an alley shaded with trees, until you reach the beautiful Santa Maria di Campagna basilica. The wall is interrupted here and there by bastions, those of Porta Borghetto – the northern communication point – to reach the summit of the southern wall along Facsal and the bastions in Via Corneliana and S.Caterina (not visible) overlooking Via IV Novembre.