Sur le pont d'Avignon?

I was taught this song at primary school. We drew pictures of people dancing on a bridge. In crayon. Probably.

Before un kilo de chansons came along, this was the song that every student of French learned.

Sur le pont d’Avignon
L'on y danse, l'on y danse
Sur le pont d’Avignon
L'on y danse tout en rond

However, I found out today that it is, historically, wrong. You probably knew this already and are saying to yourselves "Isn't he stupid? Didn't he even know that?"

Today, as I was leaving Oldham to drive home I was accosted by my mother's neighbour. He had just, that second, arrived back from a holiday in the South of France and, as there was nobody else around, proceeded to recount his holiday adventures to me. (I could hear a collective sigh of relief from all the other neighbours!)

Anyway, he explained that the song was originally entitled "Sous le pont d'Avignon" because in medieval times, under the arches of the bridge on the Ile de la Barthelasse, there were all kinds of nefarious entertainments going on, including dancing. And dancing on the bridge was forbidden.

I checked this information and he is correct. So, now we all know. Thanks, Neil.