here's some of what's inside the "Ducal palace" of Urbino,
there's a waterworks under the castle/palace,
and perhaps the most famous part of the Ducal palace, is the formerly warlord's library,
I bring up this Ducal palace of Urbino, Italy because it's an example of a castle turned into a palace before all the French Chateaus. And since the French Chateaus are inspired by Italian everthing, it seemed a good place to start!
Here's the Château de Chenonceau . . . I like this one because of the arches in the river.
The Château de Villandry . . . this one has very elaborate gardens including waterworks; this picture doesn't do it justice.
Here's a pretty good video of it
And here's the Clos Luce,
Doesn't look like much . . . but, it did house one rather famous historical figure in his dieing years - Leonardo Da Vinci! He brought the Mona Lisa with him(maybe why it's in a French museum today!). Today, engineers have made working models of various Leonardo Da Vinci machines.
Here's a pretty good video of it!