The Paris Olympics Will Showcase Iconic Landmarks and a New Sport

In one of the biggest tests for French officials, marathon swimming and triathlon events are set to be held in the Seine. The challenge is making the river safe enough: Swimming has been banned since 1923, and pollution in the waterway was once so bad that authorities studied covering it up and possibly using it for parking, according to Jean-Marie Mouchel, a Seine water quality researcher at Sorbonne Université. The cleanup has come a long way since, but recently hit a few snags—races scheduled last summer were canceled because of heavy rainfall and a faulty sewer valve. If the plan succeeds at this year’s games, marathon swimming spectators will see Germany’s Florian Wellbrock defend his gold from 2021 in the storied river, as well as rising US star Katie Grimes chase a medal.