Pergola in the “Édouard André municipal park (Pescatore),” near Villa Vauban (see photo below). It’s marked as “Blumen Uhr” in Google maps –
https://maps.app.goo.gl/51LkF3c2SsUMZPBd6
The format is simple: everyone brings something to share, along with their own plate, glass, cutlery, and napkin. It’s also a good idea to bring a blanket in case we can’t find enough space on benches or chairs – we can always sit on the grass.