Nantes or Rennes

To clarify, Nantes is indeed within the region of France long known as Brittany, though administratively it's now the capital of the Loire-Atlantique Department. We loved Nantes, and visitors there should check out the Château des ducs de Bretagne (dukes of Brittany) east of the main historic city, along with the Memorial to the Abolition of Slavery. This last is particularly meaningful to someone who has lived in the Deep South of the US. Another shouldn't-miss is the carousel outside the mechanical animals area; it's not large, but it's very, very special.

Nantes is unquestionably a gritty, somewhat hardscrabble place, and it's not to the taste of many people. We saw fewer tourists in Nantes than anywhere else I've been in France. But the charm, character and beauty are there if one works a bit to find them.

Sorry I can't add anything about Rennes; never been.

This past spring, we took the train to Rennes from Paris to pick up our rental car and then be on our way to Mont St Michel. As it turned out we spent the entire day/evening seeking unexpected urgent (not emergency) appropriate medical care. So we were redirected from one facility to the next in search of it, all in different parts of Rennes. It was quite a big city; and though I wasn't there for sightseeing, I didn't notice anything particularly charming looking about it. Now considering it wasn't my top priority, and we weren't seeking out charm, take what you will with it, but perhaps its a city from which to launch to other places? Anyway, I'm grateful to the wonderful doctor who helped us when in need, so I'm definitely thankful for Rennes and that we were not in a tiny village at the time.

Perhaps there is city center charm there.

We've been to both Nantes and Rennes but I can't say I've seen enough of either to compare them.
We visited Les Machines de L'ile in Nantes and found it less compelling than we'd hoped for. Our tour was all in French, far above my middling fluency level. It was still interesting, but not as much as it could have been if I'd known what was being said. Still, you could see the ingenious inventions. The workshop area was deserted, so nothing to see there. The elephant was the best thing.
We also enjoyed Jardin des Plantes in Nantes, a nicely laid out and whimsical garden.
We used Rennes as the anchor for our trip around Brittany, taking the train there from Paris and back again at the end. It has a very nice Centre Historique, with good shopping, restaurants, half-timbered buildings and churches. We really enjoyed "discovering" Château du Bois-Cornillé, about 35 minutes (44 km) to the east of Rennes. It's a lovely Neo-gothic chateau on 100 hectares of landscaped grounds. I say "discovering" because it was virtually deserted when we were there, and the gate-keeper seemed surprised that we wanted to drive in. We were left with the impression that it does not get a lot of visitors.

We really enjoyed the Elephant and marine carousel in Nantes and my granddaughter had seen the pictures and it was her number one request when we took her to Paris, so I took her on a day trip to Nantes and she declared it the best day of her life. For comparison her mother taking her to Taylor Swift was her second best day.
Here is our first visit:
https://janettravels.wordpress.com/2019/09/13/les-machines-de-lile-nantes/
Other than this, it was fine but not spectacular -- I liked Nantes better than Rennes but either is fine for a short visit.

Thank you for your responses. Based on your impressions I’m thinking that I should consider changing my approach and instead spend these last 2 nights in Vannes or Auray and drive the 90 minutes to Nantes airport on my last day.

Thanks,

Matt