I've built several castles and am currently finishing up a Frankenstein movie castle. For ideas I would just google "castles" to find the type of castle you'd like to build. Older square medieval castles are very different architecturally from say newer Gothic types with round towers and spires and both are even more different than Japanese castles! The original purpose of castles, was of course to provide defense, but later ones were often built as residences. Castles as residences don't have to be built with repelling assault in mind, so things like elaborate facades and windows on outside structures are okay. Castles built for military purposes are more utilitarian. Also, read up about the history of castles or stream one of the many videos or tv shows about the history of castles. I often stream something that relates to what I'm building as I build a lot to get ideas. Once you've decided on the type of castle you'd like to build you can find many layouts of that type. Most of these are tourist attractions so they have maps that are often online. You can also google castle interiors to get some ideas. I'm new so I can't link or post pictures of my castles here but if you search Captstumpy in the gallery you can look at my castles for ideas. As they say on Princess Bride "Have fun storming the castle!"
