Spandau Prison
The prison, first designed for a population in the hundreds, was an old brick building surrounded by one wall 15 feet high, another of 30 feet, a 10 foot high wall topped with  electrified wire, followed by a wall of barbed wire. In addition, some of the sixty soldiers on guard duty manned nine machine-gun armed guard’s towers twenty-four hours a day. Due to the number of cells available, an empty cell was left between the prisoners' cells, to avoid the possibility of prisoners communicating in Morse Code. Other remaining cells in the wing were designated for other purposes, with one being used for the prison library and another for a chapel. The cells were approximately 3 metres long by 2.7 metres wide and 4 metres high.