Memory in Berlin has never been easily approached. The fight over the Memorial to the Murdered Jews of Europe was long and bitter, and disagreements over the planned monuments to the gay and to the Sinti/Roma victims of the Holocaust have likewise overshadowed both projects.

None of the dust ups, though, have even come close to that surrounding the so-called Topography of Terror. But on Friday -- fully two decades after the project was originally set in motion -- the cornerstone was laid in Berlin for a documentation center chronicling some of Nazi Germany's most horrific crimes. For the second time.

"The whole process was unbearable," Andreas Nachama, head of the organization in charge of creating and managing the exhibition, told SPIEGEL ONLINE. "We kept getting different stories about when the center would be finished. Now at least we have a date we can shoot for."

The €23 million ($33 million) center, designed by architect Ursula Wilms, is to be built in the heart of Berlin on the site where the SS, Hitler's feared paramilitary group, had its headquarters as did the Gestapo, the Nazis' secret police force. Both Heinrich Himmler and Reinhard Heydrich had offices there. In 1939, the two were combined under the aegis of the Reichssicherheitshauptamt -- or Security Service Main Office -- where Adolf Eichmann, under Ernst Kaltenbrunner, managed the logistics of the Holocaust.

It is a place that has long been a magnet for tourists. As early as 1987, a temporary outdoor exhibition was set up there, consisting of informational placards and pictures plastered onto foundation remnants left over from the terror authorities' headquarters. The site hasn't changed much since, but that hasn't kept up to 500,000 visitors from filing past the display each year. Even on Friday, with dark wet clouds settling over Berlin, the site was full of sightseers.

The site's provisional nature, though, has never lived up to its historical importance. When the Wilms building is finished -- the dedication is set for May 2010, the 65th anniversary of the end of World War II -- it will join the Jewish Museum and the Holocaust memorial as part of the triumvirate of memory in the German capital.

But it has taken many years, and many millions of euros to get this far. The first cornerstone laying ceremony took place way back in 1995. It didn't take long, though, for the museum project, conceived by Swiss architect Peter Zumthor, to rocket over budget. In 2000, construction was officially stopped, after bits of the building were already in place. Despite changes to the design, Zumthor's drawings were officially pitched in 2004 and the modest beginnings to his building were torn down -- after €13 million had already been sunk into it. His resulting lawsuit was eventually unsuccessful.

Wilms' design, a blocky, single-story pavilion -- which will also house a 20,000-volume library of Third Reich documentation -- is far from the dramatic structure that Zumthor had envisaged. But with the beginning of construction on Friday, the city may finally be on the road to putting the ignominious chapter behind it.

"The construction has begun and we are confident it will be finished on time," Nachama said. "I am greatly relieved."

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