The Dungeon of Springwick Palace was for holding prisoners for a period of time. It is underground, below the Palace kitchens, and had a window, letting in sunlight in the morning.
This dungeon was hardly in use, but it is kept just in case. There are two trap doors, one from and to the kitchen, and another small one leading to outside. Sometimes, when prisoners were held captive here, guards placed them in this dungeon, using the trap door from outside. The Duke does not like it when prisoners enter his castle, therefore, the trap door in the kitchen is not used.