House of the Bulgarian Communist Party
“House of the Bulgarian Communist Party” – Mount Buzludzha – 1981
The Communists new how to throw together a fine ass building. Even if it didn’t have any true purpose. More pictures and information here.
Update 03/04/2020: I actually visited here in 2015, I can confirm it’s a long drive up, and very very cold. Though it is absolutely worth it, and an awesome place to see.