For residents of southeast Paris, the construction vehicles rumbling back and forth behind the Austerlitz train station are a loud annoyance that has gone on for too many months. But for city officials—and countless Parisians, they hope—history is unfolding behind the cordoned-off area. After years of thwarted ambitions and vague promises, the French capital, officials say, is set to accomplish a rare feat for a major metropolis: making a once heavily polluted waterway fit for swimming again.
In February, city officials invited TIME to pass through the metal turnstile behind the cordon, and see up close the cleanup of the Seine—one of the world’s most iconic rivers—which stretches for 481 miles, from Burgundy through Paris out to the sea in Normandy. Indeed, the river has defined Paris since it was founded by ancient Romans. It was along these riverbanks that merchants in the Middle Ages first set up, creating a settlement that finally dwarfed once bigger rivals like Lyon and Marseilles. And it was on the banks, too, that the world’s finest architects constructed the Eiffel Tower, the Notre Dame Cathedral, and the Louvre and Orsay museums—stunning monuments that draw millions of visitors each year to sail down the narrow stretch of the Seine that
