Now you can experience your fantasy of being imprisoned...errrr....breaking out of prison. In my campaign, the PCs are sneaking in to break someone out. Either way, what is DnD without a classic jail break scenario? Main level are the cells. Make sure to populate with interesting NPCs, such as Alexander, a murderer and homeless man who will always tell PCs he was arrested for being impolite to the Duke. The duke is a jerk, so certainly the PCs will free him so that he can murder all their favorite NPCs later. (DM's can be murderhobos too).

The second floor is a mainly the chow hall. Enjoy all your favorite prison staples, such as gruel, gruel, gruel, and gruel. Also there are torture chambers and a weapon cache. This floor is a great place to start a prison riot to distract the guards while you make your escape.

The last floor is the top of the tower. It has a large bonfire. Maybe PCs can throw a rope down and escape from here?