Built in vanilla, I used the Alhambra palace in Portugal as inspiration.
It certainly is form over function. Although you can fit a tiny living area in the nooks and crannies of it, it's mostly for show and more decorational.
It's 90% grausten stone and I basically farmed a tiny ashland island of all its grausten for it.
Further decoration is an option. More red banners and perhaps some trophies is the way to go.