Shouts of excitement echoed along the Seine at morning as Parisians legally plunged into the river for the first time in more than 100 years.

Designated swimming areas, including two new wooden decks near the Eiffel Tower and Île Saint-Louis, opened to the public as part of a long-anticipated initiative to revive urban swimming in the heart of Paris.

Ahead of the opening, a municipal worker cleared patches of algae from the water with a net, and soon, eager swimmers lined up with towels in hand, ready to jump in. Cheers and joyful cries filled the air as the first swimmers entered the emerald-green river.

Strict safety measures were in place, including mandatory bright yellow lifebuoys for all swimmers and lifeguards stationed along the banks. The river's mild current served as a reminder that the Seine remains a bustling, living waterway.

“It’s amazing to swim right in the center of the city, especially with the heatwave we’ve had,” said Amine Hocini, a 25-year-old construction worker from Paris. “I expected it to be cooler, but it’s warmer than I thought.”

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The return of public swimming follows a €1.4 billion ($1.5 billion) clean-up effort linked to last summer’s Olympics. Authorities say the Seine now meets European water quality standards on most days. Mayor Anne Hidalgo, who took an early swim last year, attended Saturday’s event, holding up a bottle of river water to demonstrate confidence in its cleanliness. Environmental officials confirmed bacteria levels were well within safety limits.

Swimming in the Seine had been banned since 1923 due to pollution and river traffic risks, with few exceptions. Swimming outside approved zones remains prohibited.

Tourists and locals gathered to watch from the decks and riverbanks, some applauding as swimmers climbed back onto the platforms, smiling and dripping wet. Others, like longtime resident François Fournier, remained hesitant.

“Honestly, I wouldn’t risk it yet,” said Fournier, watching from a nearby bridge. “I’ve seen all kinds of things floating in the Seine. I’ll wait until it’s really spotless.”

Though occasional debris like leaves or plastic wrappers floated by, the strong sewage smell that once plagued the river was gone, replaced by a mild, earthy scent.

“This feels so classy, swimming in the Seine near Île Saint-Louis,” said 43-year-old Parisian Lucile Woodward. “Sure, there are always concerns before swimming anywhere, but I think this is probably the most tested water in the world now. The city can’t afford any slip-ups.”

She smiled and added, “My skin is fine.”