You will not believe this until you see it. Unlike many of the 'glitzy' old churches (which are stunning in their own right), this one is understated but absolutely fantastic in its simplicity. The architecture is astounding. There is a major archeological dig underway and the presentation is as good as anything you will see anywhere in the world. The museum of Gallo Roman artefacts is incredible.
The Best thing is that this place is NOT a Tourist Mecca....... You can stroll around in your own time and it is a "donation" rather than a fee, we gave them a donation of what we would have paid in some of the other places simply because it is worth it.
And while I am talking about Auxerre. Base yourself here if you are in Bourgogne, because it is unspoilt and natural and NOT over run by tourists. Great shops but normal people. Great streets full of beautiful buildings.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.