Now THIS is cool! Looks like some kind of port for large ships to stop at! I like the strong angular design, and all the little houses and shops built into the walls. Looks like a small town or city, built as a go-between for ships.
At this captured moment there is only the "seen"-side of your picture designed but yesterday we continued designing the back- and inside of your castle with big halls, small ways and several stairs and rooms to reach all the buildings along the castle. When this is done, we plan to create some nice "redstone"-gimmicks, like hidden doors and some mistory-things. Maybe we can plan some special events inside this castle in Minecraft. The options are endless