The Långholmens Fängelsemuseum describes the history of the Swedish penal system.

You can see how must be the life inside the Kronohäktet prison before it was turned into a hotel/hostel.

You can visit a typical cell used between 1845 and 1930, read about Sweden's last executioner, Anders Gustaf Dalman, and see a scale model of the guillotine imported from France and used only once.