Nestor Makhno and his Makhnovists weren’t perfect but I think its probably the closest we’re going to get to seeing a working anarchist society. It seemed like it worked for a short time.

Also note the mutial aid systems that spring up in the wake of some disasters could probably be considered temporary anarchist societies. Rebecca Solenit wrote a book about this but I haven’t gotten a chance to read it yet. A Paradise Built in Hell. I hear its good but I can’t say that with firsthand knowledge