Most people don't really travel to gay Paris for the beach possibilites, seeing as there aren't any! Saying that, every summer the banks of the river Seine and the city's canal come alive, and are transformed into a seaside resort with the 'Paris Plages' event.
The City of Light can get very sticky during the summer months, so, from July to early September, residents and tourists alike can make the most of the warm weather with free deckchairs, sun umbreallas, and even shipped-in sand in front of the river Seine. At the canal and Bassin de la Villette, there's even the chance to cool off and go for a dip in the water (we can't guarantee how clean it is!).
So, if you're in Paris during the hot, summer months, definitely give Paris Plages a try and make the most of the warm weather!