Seine is the longest river in northern France, with a total length of 780 kilometers (485 miles) and a total drainage area of 78,700 square kilometers (30,400 square miles) including tributaries. It is one of the rivers with a long history in Europe, and its drainage pipe network accounts for most of the inland river shipping volume in France. From the early Middle Ages, it was first a river in Paris; Paris is built on some major ferries of rivers, and the interdependence between rivers and cities is close and inseparable. Paris is located in ile-de-france, the affluent center of the Seine River basin. It is the cradle of the French monarchy and the core of the expanding French nation-state, and it is still the center and metropolitan area of France.

The Seine River originates from Tasselot Mountain in Codol, Burgundy, with an altitude of 47 1 m (1.545 ft). When it winds through the porous limestone village on the other side of Chatillon, it is still a stream. It flows from Burgundy to the northwest and enters the champagne above Trouvat; This is a solid gully on both sides of the Champagne-Dry Chalk Plateau. When it flows near Romilly and joins the Aubu River, when it flows near Montero in the west, the valley widens, where it receives the Yone River from the left bank. The Seine turned to the northwest again, built a trench-like valley, crossed ile-de-france and ran to Paris, passing through Melen and Colbe. When it enters Paris, it joins its great tributary, the Marne River, on the right bank. After winding through the metropolis, it flows into the Watts River on the right bank. When passing through Paris, the Seine River has been trimmed, and the passage between the docks on both sides of the strait has narrowed. It flows along the winding river, passes through Normandy under Mantes-la-Jolie, and reaches the mouth of the English Channel. Its wide estuary opened rapidly, extending 26 kilometers (16 miles) through Tancavell to le havre. It often has tidal bore.