The Seine river flows 776.6 kilometers from its source in the Cote-d'Or (at St-Germain-Source-Seine, north of Dijon) to the sea at Le Havre. It is navigable from the confluence with the Aube river at Marcilly. From Paris to Le Havre it is France's busiest waterway. Four other navigable rivers flow into the Seine: Yonne, Loing, Marne and Oise; these rivers connect into the inland waterway network of France - north, east, and south. The combined Seine Basin dominates the waterways of northern France. The Seine is unusual in its many boucles, smooth curving loops that cut across the straight-line path to the sea. The limestone cliffs shown above are at Le Petit Andely, Normandie.