Carcassonne is a French fortified city in the department of Aude, region of Occitania. It is the prefecture of the department. Inhabited since the Neolithic Period, Carcassonne is located in the plain of the Aude between historic trade routes, linking the Atlantic to the Mediterranean Sea and the Massif Central to the Pyrénées. Its strategic importance was quickly recognised by the Romans, who occupied its hilltop until the demise of the Western Roman Empire.