While in Paris, we tried a couple of times to see the Marc Chagall ceilings in the Paris Opera. The first time, we arrived after viewing hours. We asked about how to see them and were told that there was no guarantee, unless you purchased a ticket for a performance. Visiting hours were between x and y, and you could get in for a fee... if there was not a rehearsal in progress. We planned to be in the area again for another attempt at a viewing, but, there was, indeed a rehearsal.
So we did not see the Chagall Ceilings.
As we approached Nice we thought our second opportunity to see some Chagall would make up for the earlier disappointment. Nice houses the National Museum of the Biblical Message of Marc Chagall. Our trusty GPS device lead us directly to the museum. We parked in the lot around the side and walked over to the entrance.
There we were told by the local authority that the museum was undergoing renovations and would only reopen on Thursday (the day of this writing in Florence, Italy, not Nice, France)!