I have a castle built, but I have no idea what else to build. All I have so far besides the castle is a blacksmith.
dungeon or torture room under the castle
secret entrence and exit
make a throne room and a safe under the throne chair
make like horse stables or a pen to breed pigs sheep chicken ect.
Throne Room, huge dining hall, Small church or houses in it, Secret tunnels underground, graveyard.
Palace or cathedral is better. :3