Buzludzha Monument, Bulgaria
http://blog.flickr.net/en/2012/05/10/buzludzha-monument-bulgaria
The UFO-like monument on the Buzludzha peak in Bulgaria, built by the countries former communist regime to commemorate the events in 1891 when the socialists assembled secretly in the area to form an organised socialist movement, was opened in 1981, but abandoned after the fall of communism in Eastern Europe.
http://www.flickr.com/photos/markoneill/5768749965
Today, the trespassing visitor can explore the site’s interior, finding traces of the mosaic frescoes that once artfully decorated the walls and exploring the debating chamber with the hammer and sickle symbol still blazoning the centerpiece of the ceiling.
http://www.flickr.com/photos/scouseandjules/4640543938/in/photostream
