The cathedral is very impressive, both inside and out.
There's also a beautifully restored clock tower, which looked a little too steep for us, so we didn't take the tour.
We saw the spot where Joan of Arc was put to death, but it's marked only by a garden in the old market. This neighborhood also has the oldest auberge (inn) in France. There are lots of half-timbered buildings in Rouen, some of which are probably authentic. It's a very picturesque town.
I was a little disappointed that we didn't have time to see the Flaubert museum because I think Flaubert is among the best novelists of all time.
Oh, and to top it off, Bill bought a very nice piece of Camembert at the market in Rouen, and when we stopped at the boulangerie on the way home from the Métro, the bread was still warm!
All in all, a very pleasant day.