The city walls. Although this is the quintessential medieval fortified town, it appears to me that it was rarely useful. After the Roman empire collapsed, the town was conquered by the Visigoths, the Arabs and the Franks. Later, during the aforementioned Cathar crusade, it surrendered to the crusader army. Ironically, one of the rare cases where the fortifications worked was when the Cathar lord tried to retake his castle from the Crusaders a few years later...
City fortifications as seen when entering through the Narbonne gate. There were two portcullises operated from two separate rooms - bribing only one soldier wouldn't work!
This one shows a nice view from the inner castle over the fortifications down to the new city. I particularly like the tower in the centre of the photograph. According to information provided during the tour it dates back to late Roman times as can be seen from its U-shaped foundations: flat towards the town, rounded towards the outside. Also, Roman defensive towers still had larger windows than later Medieval towers.
Another historic town we stopped at is Lagrasse. It has an abbey ruin, but depicted here are a bridge and the outer houses.
On a nature walk near Lagrasse we found this Ruta