I'm a Dm and i'm going to be sending the party into a prison to break someone out. They are 13th level, a rogue, fighter, and bard. I'd like to ask for some ideas on what to put in the prison. A bit about what i've got so far:
The prison is run by all an independant unit but houses all of the worlds most vile beings, from common race mass murderers to Illithids, to Giant undead dragons and gargantuan abberations. No one leaves. Ever. It's flavor is that of Alkatraz, Arkham, Azkaban, and The Tower of Latria (demon's souls). A really grimy, gritty, haunted and insane place. It's run by a beholder, with common race guards, Wraiths under control, and The Warden, who's a human assassin bounty hunter type. The idea is for this to be a complex of challenges for the players, and as such, there is no flying, and all of the prison cells are enchanted to make the prisoners speak gibberish.
The problem i'm having is simply filling rooms. I just dont know what to do with all of the space a prison might have and still keep each place original.