It was also a race against the clock, as the excavators dug deeper and the workers removed more reinforced steel. Why wasn't Conrad able to stop going there? He considers the question, gazing at the slides spread out on the lightbox in his Berlin office, then says: "Being down there and hearing the echo of your own footsteps, discovering things from a completely distant chapter of history -- it was that feeling of traveling back in time that fascinated me so much."
So he kept pushing his luck. Once he was scared half to death when he suddenly came across another man in the Reichskanzlei bunker. "It was unbelievable," he says. "He was sitting there as calm as could be with a miner's lamp, drawing the gloomy scene on a small easel," Conrad says. Was this a kindred spirit, another person interested in capturing architecture before its destruction, no matter how despicable the behavior of the people who originally constructed it? To this day, Conrad isn't sure. "We talked to each other, but the mistrust was too great," he says. "He didn't dare to ask me why I was there, and I didn't dare to ask him either."
It made for a grotesque scene: Two men holding their tongues out of fear of the communist dictatorship, inside a Nazi bunker. After a brief pause, both went on about their work, one with his camera and the other with his charcoal.
A couple of visits in, Conrad finally found the entrance to the infamous bunker where Hitler and his inner circle barricaded themselves when the Red Army reached Berlin. The complex consisted of a first bunker constructed in 1935 and then the actual, far more bombproof "Führer's bunker," which wasn't finished until 1944. But Conrad was disappointed by what he found. Neither part of the bunker complex contained the "original setting of insanity" he had hoped to see. "Too many Allied soldiers and curious Berliners had already been through there in the first years after the war, and all of them took souvenirs," he explains.
Conrad certainly found some items: decaying bits of furniture, projectiles, the epaulet of a high-ranking Wehrmacht officer, a gas mask and empty sparkling wine bottles. But the "Führer's bunker" itself, constructed from 1943 to 1944, was so flooded with water that it was hardly possible to get inside. It also now consisted of just one large room, since the Soviet army's demolition blasts had broken down the interior walls. In the first bunker, though, the one constructed in 1935, Conrad believed he had found the room where Magda Goebbels poisoned herself and her children with cyanide shortly before the end of the war. "The bunk beds were halfway collapsed, rusted and standing in the groundwater," he says.
It was after this visit that Conrad was caught for the first time. Police examined the contents of his leather shoulder bag, patted him down and quickly found the film he had hidden in his socks. But to his surprise, they gave him comparatively little trouble. They didn't accuse him of trying to escape East Germany either. "They didn't really understand what I was doing down there, they just told me I should cut out the nonsense," he says. But Conrad didn't cut it out. In fact, the fake construction worker was caught four more times and had a dozen rolls of film confiscated.
A Dream Come True
Then, in 1989, it was all over. The removal work ended and the rest of the "Führer's bunker" -- the floor slab and the external walls -- were filled in with rubble, sand and gravel.
Just a few months later came the demise of another massive concrete construction -- the fall of the Berlin Wall made Conrad's dream of studying architecture, denied to him in the GDR, possible at last.
In his spare time, though, Conrad remained true to his old passion. To this day, he seeks out lost worlds, photographing abandoned barracks, apartment blocks and factories shortly before they are torn down. These days, though, he no longer has to disguise himself as a construction worker.
Additional photos can be viewed at the Lumabytes agency website.
This article originally appeared in German on einestages.de, SPIEGEL ONLINE's history portal.