I visited Bavay in northern France several years ago, returning from Saulzoir, where Julius Caesar had once defeated the Nervii. The ruins of Bavay were something of a bonus after a day that had been very well-spent, and we were not in a particular hurry. So, we were too late to see the exhibition, but could take some photos of the forum and the basilica. They were impressive, which comes as no surprise, as Bagacum, as it was called, was some kind of showcase of Roman power.
Although I still hope to see the exhibition, some information is already available here.