31 October - Samhuinn festival

OK OK it's not French, but... it looks like good fun!
More info on the Festival and Beltane's activities

"Come all and witness the ancient Celtic Samhuinn festival! It was the
Celtic New Year, the Day of the Dead, and marked the beginning of
winter. It was the time of year when the veil between this world and
the next, between mortality and infinity, was at its thinnest and
spirits were said to roam the lands...

Come and celebrate, feast and carouse in our procession of fire,
drumming, music and performance art! See the fight between waning
Summer and the growing darkness of Winter!

The Samhuinn procession begins from the Castle at 9 pm and ends up on
the Mound (beside the National Galleries) for performances on the
stage. It is presented by the Beltane Fire Society, a not for profit
organisation run by volunteers, the event is free but to keep it free
they rely on donations from the public on the night, so if you see
someone shaking a bucket near you, give them some change please."

There are also after-parties but I am not sure where, as have got conflicting info: either The Bongo Club or Cabaret Voltaire. Or maybe both. Who knows? (add in comments if you do! ta!)

All proceeds go the Beltane Fire Society