According to the website
Situated in the heart of Touraine, in the Loire Valley, Azay-le-Rideau was built during the reign of François I by a rich financier wishing to establish his brand-new title of nobility. A small gem of the first stirrings of the French Renaissance, decorated with carved stone lacework, the château was embellished over the centuries by succeeding generations, with an entrance inspired by that of Vaux-le-Vicomte and an English-style landscaped garden. Yet it never lost its harmony. Still today, Azay “bathes in the Indre River like a princely creature” (Honoré de Balzac).
Which descibes it rather well, really. Form the outside it looks like the owner picked up the "Bumper Book of Chateau Cliches" (or maybe "Chateaux pour les Nuls"), couldn't decide what to have so went for the lot.
There is no doubting though - it is very pretty, and is well worth at least half a day of anyone's time. Being so close to Villandry they would make perfect partners if you only had one day to spend in the Loire Valley and wanted to see a pair of "proper" chateaux. Lucky Pat and Geoff even managed to travel to Azay le Rideau in Célestine, which made the day even more stylish.
You will notice I haven't abbreviated the name to just "Azay". This is to distinguish it from Azay-le-Ferron, which is about 10km from us in Preuilly sur Claise (and many other Azays as well). We have been told that Azay is Old French for "Assay" (although online all the dictionaries seem to say old French is "assai"), and thus indicates that mining or the assaying of metals took place in the area.