Palace of the Soviets - Credit: Wikimedia Commons
The Palace of the Soviets (, Dvorets Sovetov) was a project to construct a political convention center in Moscow on the site of the demolished Cathedral of Christ the Saviour. The main function of the palace was to house sessions of the Supreme Soviet in its wide and tall grand hall seating over 20,000 people. If built, the tall palace would have become the world's tallest structure, with an internal volume surpassing the combined volumes of the six tallest American skyscrapers. This was especially important to the Soviet state for propaganda purposes. Read more on Wikipedia
Source: en.wikipedia.org