I had one day to spend doing touristy things while in Europe, so I decided to spend my day by taking the train out to Carcassonne. The fortified city consists essentially of a concentric design of two outer walls with 53 towers and barbicans to prevent attack by siege engines. The castle possesses its own drawbridge and ditch leading to a central keep. The walls consist of towers built over quite a long period. One section is Roman and is notably different from the medieval walls with the tell-tale red brick layers and the shallow pitch terracotta tile roofs. One of these towers housed the Catholic Inquisition in the 13th century and is still known as "The Inquisition Tower". It's a spectacular place, and I enjoyed spending the day exploring it.