The Seine is the third longest river in France and runs through four regions. It divides into two: left bank (rive gauche) and right (rive droite) There are 37 bridges that cross it.

Bathing was banned in 1923 due to high pollution. The goal is that it can reopen to the bathroom in summer 2024, for the Olympic Games in Paris, and for the general public a year later, in 2025. The challenge of purifying the river and ensuring that it meets the environmental requirements was gigantic.