In Nuremberg, Albert Speer planned to build the Deutsches Stadion, a gigantic large stadium with seating for about 420,000 spectators and with a height of about 90 meters. Speer understood that the visibility from the top floor could cause problems for the spectators to be able to see the events down on the pitch. To investigate this, Speer, had in Oberklausen, about thirty kilometres east of Nuremberg, built a full-scale section on a slope, measuring 100 meters long, 70 meters high, 75 meters wide and with a capacity for 42,000 spectators, equivalent to one-tenth of the planned stadium. A lage tower next to section were also built. Hitler was extremely interested in the construction and visited the construction site together with Speer in March 1938. The Deutsches Stadium itself did not get any further than some groundwork before all work was interrupted due to the outbreak of war in 1939. All work and tests at the test facility in Oberklausen were also discontinued.
Current status: Partly preserved/demolished with information board (2014).
Location: 49° 34´04" N, 11° 34´27" E
Get there: Car.
Follow up in books: Speer, Albert: Inside the Third Reich (1969).
For those who want to, it is possible to walk up to the top, there are trampled paths a little bit everywhere, but it is not easy given the slope. At the top you have a nice view of the area but it is doubtful if the one who sat on the top row really could have seen what was happening down on the ground level.