Advance reservations are required before visiting this museum as it is small and does not accommodate large groups of people. It is a unique museum that tells the stories of the university prison in the city, as Heidelberg University has had an independent jurisdiction and the legal right to detain students who violate the laws of the university since its founding in 1386. The university has imprisoned students for many reasons and the most common reason was singing in the voice High, and the students were sentenced to spend between two and four weeks in prison. The imprisoned students would spend their time decorating the walls, writing texts on wooden tables, and playing cards with friends. The prisoners used black wax smoke and black coal to paint on the walls. The prison was closed in 1914 and since then visitors come from all over the world to see the murals covered with student writings and drawings.