Nazi Party Congress building. A large auditorium (designed to be larger than the Colosseum in Rome) was needed for this once a year event. Commissioned by Hitler the Hall was designed to hold over 50,000 people, but was never finished. The horseshoe-shaped building covers a total area of about 300 x 300 metres. The scale of this structure is overwhelming with an immense arcade running around the lower level of the u-shaped structure.