Originally an Iron Age fortification, the Romans expanded the site into a proper settlement. From then on, the fortified hilltop was continuously expanded by its rulers until the Treaty of the Pyrenees in 1659. Like many towns in the region, Carcassonne’s Cathars were targeted by the Albigensian Crusades, and expelled from the city when it surrendered. After being demilitarized by Napoleon, the town fell into disrepair, almost being demolished. Fortunately, a campaign to save the town brought in architect Eugène Viollet-le-Duc, one of the founders of the modern science of conservation, who expertly restored the fortifications to their former glory. Thanks to these efforts, visitors are able to explore the ramparts, the Château Comtal, the Cour du Midi remains of a Gallo-Roman villa, the Inquisition Tower, Gothic basilica, and the torture chamber at the Exposition.