The Seine flows through Paris before reaching the English Channel.
The river rises on the Langres Plateau in northeastern France and runs generally northwest for about 777 kilometres. It passes through Troyes, Paris, and Rouen before entering the English Channel at an estuary near Le Havre and Honfleur.
Paris developed around the Seine, especially on and beside the Île de la Cité. The river supported transport, trade, drinking-water systems, and the growth of the city. Many famous landmarks, including Notre-Dame Cathedral, the Louvre, and the Eiffel Tower, stand close to its banks.
The Seine is sometimes confused with the Loire, France's longest river, which flows into the Atlantic farther south. The Seine's historic central Paris riverbanks were added to the UNESCO World Heritage List in 1991.