Part Cold War relic, part crumbling UFO, the Buzludzha Monument was once the epicenter of the Bulgarian Communist Party. Built in 1980 and only open for eight years, this mountaintop modern ruin was once a hub of Eastern Bloc activities that was abandoned after the fall of the Soviet Union. Since then, harsh winter conditions, looting and a lack of formal upkeep has resulted in the building's steady decline. The Soviet red star that sits atop the building is three times larger than the one atop the Kremlin—now, though, all that star signifies is that party's past rule.