The main defensive tower at Schlitz Castle. It was built in the 13th Century and is 37 meters / 121 feet tall.
Originally the access was at the level of the fourth floor of the adjacent building, and the bottom of the tower contained a prison.
Prisoners were lowered down by rope, and were kept in complete darkness, like potatoes.
Notice the fixtures at the top of the tower to pour or throw molten lead, hot oil and other nasty fluids and objects on persons below.