It is a place that for years was on no map. A place you were taken in, isolated and held without human contact for years at a time. A place that many people emerged from broken and beaten. But not Hans Eberhard Zahn.

Zahn was arrested by the East German Stasi in 1953, accused of spy activity. He was held in what is called the “Old” building inside Berlin’s Central Stasi Prison for seven years. Seven years in the dark with no one except his captors to talk to. Many people in his situation lost their minds in the darkness. Zahn did not. Relying on his love of Goethe and Shakespeare, of learning and life, he was able to survive his ordeal and emerge a whole human being.

Zahn takes visitors through the prison complex, showing them a cell similar to his own and re-enacting his interrogations — quoting Dante and Shakespeare along the way. He says it’s a “triumph” for him, to be able to educate people about the Stasi. Also that he will not allow himself to be “loaded mentally” by his experience.

After his release from the Central Stasi Prison in 1960 Zahn finished up his studies in psychology and became a lecturer in the subject. But it’s not only his own ordeal that ties him to this place, Zahn’s wife was also held by the Stasi, but at a different time than he was.