Not only are three Olympic and Paralympic events - triathlon, marathon swimming and Para-triathlon - scheduled to take place in the Seine in central Paris, but by 2025 three open-air swimming areas will be accessible from the quayside.

Triathlon and marathon swimming are scheduled to take place in the Seine, where it has been illegal to swim for more than a century. Despite the city’s efforts to clean up the long-polluted river, the water has tested unsafe for humans in recent weeks, and cleaner on other days. The Games run from July 26-Aug. 11.