The Olympic Games in Paris generated a lot of excitement around the cleanup project of the Seine River, where triathlon and swimming competitions took place. And there’s more to come: Mayor Anne Hidalgo plans to open three public swimming spots on the Seine by next summer, and similar projects are in the works in Boston, London and Amsterdam.

But these plans to develop “blue infrastructure” — which can help cool cities, promote biodiversity and improve quality of life — won’t be the first. Here are six European cities that have successfully opened up their waterways for swimming.

Paris

Dip into floating swimming pools filled with filtered canal water.

Some Parisians can still remember a time when the banks of the Seine were lined with floating swimming pools — with views of the Pont Neuf and the National Assembly. (The Piscine Deligny was built on a floating barge in the Seine in the late 1700s; it sank in 1993.)