Over the couse of three days I managed to visit 11 if the sites using a combination of trains and buses:

Chambord - (bus #18 from Blois) a huge but elegant structure set in spacious grounds. The frescoed ceilings were admirable as was the double circular staircase. But most interesting were the multitude of chimneys, turrets, dormers and other rooftop embellishments.

Cheverney - (bus #18 from Blois) smaller but equally elegant and a more colourful interior. Some nicely landscaped gardens too.

Blois - (train from Tours) interesting sculptures but not much else

Chinon - (train from Tours) more of a castle than a stately home. Took the lift from the town centre to the upper town and walked around the ramparts to reach the entrance. Great views of the Loire.

Azay Le Rideau - (train from Tours) a spartan interior but some interesting paintings and tapestries. Located on an island.

Saumur - (train from Tours, then bus #32 from the town centre up to the chateau) a castle built for defensive purposes.

Langeais - (train from Tours) a moat, drawbridge and keep, but very little else.

Orleans - a huge bronze statue of Joan of Arc

Chaumont - (train to Onzain, then walk across the bridge) an austere looking stately home.

Amboise - burial place of Leonardo da Vinci in the St Hubert chapel.

Tours - a small chateau by the river. Also interesting was the Museum of Compagnonnage (tradesmen and artisans) in St Julien's cloister