The Seine in Paris is open for swimming

Swimming in the Seine is an increasingly popular tourist attraction in the French capital — and a must-do for Parisians themselves. Thousands of people have enjoyed a dip in the river since three public bathing sites opened last month, the first in over a century.

- By SYLVIE CORBET

The swimming areas are expected to get even more crowded as a heatwave arrives in the region on Tuesday. Paris has been placed under "high vigilance" by national weather service Meteo France, with temperatures up to 38 degrees Celsius expected.

At the Grenelle site in the west of Paris, visitors swim and sunbathe with a unique view of the Eiffel Tower, with small fishes darting near the surface.

Water quality is tested daily to conform with European regulations. Swimming in the Seine had been illegal since 1923, with a few exceptions, due to pollution and risks posed by river navigation. The new bathing sites are possible following a 1.4 billion euro ($1.6 billion) cleanup that made it suitable for Olympic competitions last year.

"Imagine that," said Constanze Martens, a tourist from Mexico. "Swimming with view of the Eiffel Tower and in pure natural water, clean, safe, and with all this lovely people too, you have every age here."