After receiving widespread praise from architects worldwide, the Soviets started construction on their Lenin monster house in 1937, spending two years on the foundation alone.
Three people died by just constructing this plaster model.
Was Never Built Because ...
The Nazis. It's always the Nazis. Since the war was coming closer to Moscow, materials were needed and the steel was ripped up and used for railroads or military fortifications or commemorative WWII gravy boats or something. By 1945, the site for the Glorious Hall of the Soviets was nothing but a huge pile of rubble and concrete. Even after the war was over, the Cold War put strains on the same resources and the project never gained momentum again. Especially after Nikita Khruschev turned the site into the world's bitchinest and biggest outdoor pool.
Have fun playing Marco Polo in the carcass of a failed dream, comrades!