The Seine is a river in North France and has a length of 780km (485 miles). After the Loire it is the second longest river in France. Its spring lies in Langres Plateau and from there the river flows in a north-west direction through Troyes, Paris and Rouen. It flows into the English Channel near Le Havre. In addition the Seine is connected over canals with other rivers like the Loire, Rhône, Meuse, Schelde, Saône and Somme. The Seine is a very important river for trade.
The following link gives more information: