Motivated by a sweltering heatwave, Parisians have been queueing up to take a dip in the river Seine after it reopened to bathers following a ban dating back to 1923.
Since city hall delivered on a promise to make the river safe for swimming ahead of last year's Summer Olympics, and then for everybody, more than 50,000 people have taken the plunge this summer.
"What a great opportunity," said Ghislaine Roche, 66, from southern France and more accustomed to swimming in the open sea than in an inner city waterway.
But with outside temperatures in Paris spiking to 35C this week, she and her husband decided that "this is the right time" to cool off in the Seine by the historic Ile Saint-Louis river island across from the Latin Quarter, one of the capital's three sites open to the public.
Although hopefuls showed up early, there was already a queue by 10am local time at the site, which admits only 150 people at any one time.
The fact that the water looked a little green, and lacked designated swimming lanes, dampened nobody's enthusiasm.
"It's extraordinary to be able to swim in natural water, and not in the municipal pool," said Alain Desaunay, 62, who lives in a Paris suburb.
"I needed to cool off," he said.
The water, at 24C, was "just perfect", according to several bathers.
Summer downpours in July caused temporary closures of the bathing spots as the rain washed waste into the river, pushing its pollution level beyond safety limits.
But despite those setbacks, the overall Seine swimming season "has been a real success", said Stephanie Le Guedart, deputy director for youth and sports in Paris's city hall.
"We're very happy, the crowds have been unbelievable," especially since temperatures jumped, she said.
The bathing areas are to remain open until the end of August.