From the Introduction:
The town's lockup is not so much a prison as a guardhouse of the city watch with slightly more cells then usual. The front of the square little fortified building, with its only entrances, is as a matter of fact taken up by the rooms of the watch. Only the other three wings surrounding the inner courtyard contain cells. Cramped little rooms with only a single narrow and barred window high up. But most suspects are only held here for a short while until they are put on trial. And the few convicted criminals returning here usually only stay until the executioner and his henchmen have the gallows set up in the lockup's courtyard.
The lockup is a rather new construction, set up in the place of an older keep. Today only the moat surrounding the lockup still reminds of this old fortification. Its water deep enough that most people would have to swim to cross it and the ledges both on the out- and the inside high enough above the water level that no one would be able to pull themselves up without help. A single simple wooden bridge crosses the moat, right at the structures front entrance.
On the outside the building has no windows on the ground floor. Even on the first floor only the guards ready room has windows towards the street. The guard towers again have windows on their third floor. The holding cells in turn only have one narrow window, barred with sturdy steel bars, each. The ones on the ground floor facing inward into the lockup's yard and the ones on the first floor facing out towards the street. A single door leads to the courtyard where the towns hangman sets up the gallows if they are needed.