The big boss vamp's castle lies in the center of vampire territory. Yes, Dracula is a show off. Hence the big ass castle with many floors, countless rooms, a drawbridge, and battle turrets. It is surely a sight to behold.
Dracula isn't the only one who lives here of course. His family resides here, as well as servants, humans who will serve as dinner at some point, and anyone whom Dracula finds worthy. Surrounding the castle is the Vampire city -- homes of the many vamps under Dracula's reign.