Loches?

The historic “ Royal City of Loches” has one of the oldest castles in France that goes back to the 9th-century. The history of Loches is more impressive than the scale of the walled city. It was a residence for the kings of France from about 1250 to 1450 and intermittently after that. In 1429 Jeanne d’ Arc visited King Charles Vll at Loches castle after winning the Battle of Orleans. In a move to unify the French and drive the English out of France, she convinced the king to be crowned in Reims Cathedral, where all French Kings had been crowned. .
With a car, Loches can easily be reached in 30 minutes from Amboise. By train or bus, it takes 2.5 hours. Market day is a perfect time to visit.

Charming small town. I think your plan is right for the place.

The market in Loches is well worth visiting, it runs from about 9:30 to 12:30 Wednesday and Saturday mornings.

The town itself is also well worth visiting, having plenty of medieval and renaissance architecture, narrow winding streets, and a whacking great chateau. It benefits greatly from not being Amboise and featuring heavily in the RS books.

To me, the interior of the chateau of Loches was more interesting than that of the other, better known ones. Some nobleman (French? Italian?) was imprisoned there, and wiled away the time decorating the walls of his room.

That would be Ludovico Sforza, Duke of Milan.

https://daysontheclaise.blogspot.com/2021/12/it-looks-like-ludovico-lies-in-loches.html?m=1

We thought Loches was great, spent more time at the chateau than the town and I don't think it was market day. There's also a good church near the chateau with a piece of a Roman column. Nearby is the town of Descartes, where the great philosopher grew up ("I think, therefore....") and there's a museum about him and his philosophy.

Thank you so much for the replies. Loches is on my itinerary!