Between 1933 and 1938, Hitler supporters flocked to a huge complex in Nuremberg for a series of mass Nazi party rallies. The once-imposing grounds, where parades and processions were held in celebration of the Führer, are now crumbling. Nuremberg officials are about to undertake a controversial plan to conserve this epicenter of the city’s tortured past.

The Nazi party rally grounds, or Reichsparteitagsgelände, stretch for more than four square miles across southeastern Nuremberg, which Hitler declared the “City of Nazi Party Rallies” in 1933. Designed by Albert Speer, Hitler’s chief architect, the complex boasted sprawling tent encampments and barracks where visitors could stay during the week-long rallies, a grand parade street that spanned more than one mile, a Congress Hall that could seat 50,000 people, a stadium where tens of thousands of German youths displayed their vigor before the Führer, and the so-called “Zeppelinfeld,” a fortification-like arena where Hitler surveyed his adoring supporters from a large grandstand.

Problems, however, lurked beneath the site’s grandiose veneer. Few of the grounds’ planned components were finished completely before construction came to a halt with the advent of WWII. And the structures that did exist were hastily built, which in turn means that the complex has not held up well over time.

“The damp is the biggest problem,” Daniel Ulrich, head of Nuremberg’s construction department, tells Catherine Hickley for the Art Newspaper. “The original construction was quick and shoddy. It was little more than a stage-set designed purely for effect. The limestone covering the bricks is not frost-proof and water has seeped in.”