The Loire River is the longest river in France, 630 miles (1,010 km) long. It rises in the Cévennes Mountains in the southeast and flows in an arc northwest through Orléans and then southwest to the port cities of Nantes and Saint-Nazaire where it empties into the Bay of Biscay. Altogether the Loire drains an area of about 44,000 square miles (70,600 square km) - approximately one-fifth of France. Once prone to flooding, the Loire is now managed with a system of dikes. A network of canals connects the river to the Saone, the Rhone and the Seine Rivers. The Loire river valley, with its medieval châteaus and ancient vinyards, is rich in history and is often thought of by the French as the cradle of French civilization.