The state of Constantine witnessed the passage of many different civilizations on its land, including Punic (Carthaginian), Roman, Byzantine, Islamic and others, the oldest of which dates back to the fourth geological era. These civilizations left many historical sites, rock monuments and ancient caves, the most important of which are the ruins of Tidis, the city of the Kasbah and the cemetery. The megaliths, the Mausoleum of Masinissa, the Palace of Ahmed Bey, and a group of mosques and bridges of the ancient city of Constantine.