Hello Néhémie and welcome to OSM.

It looks like you have added some historic city walls. However, it looks like some of them are not still standing, i.e. are ruins, from satellite images. If that is the case, please don't use barrier=city_wall for them, which would imply an actual, existing impassable city wall. Use historic=citywalls instead.
There are parts of wall structures to the east which do look like they qualify to get this tag, though.

Thank you very much,
Crsi