The concrete UFO looming over Shipka Pass is central Bulgaria's most peculiar sight. This former assembly hall slid into disrepair after the fall of communism, but its space-age silhouette has turned it into an irresistible stop for travellers. At the time of writing, authorities had reopened its front doors after months of barring them shut and forbidding visitors. We strongly recommend admiring it from outside: there's a high risk of injury from broken glass or falling masonry inside the unmaintained building.
Buzludzha Monument stands on a 1441m peak overlooking the pass. On the drive up, look for the steely monument of clenched fists. Next to the UFO, the concrete shard pointing skywards is crowned with a red star. Rumours that the star was made of rubies led to locals looting and chipping the site (it's really glass). While local people have mixed feelings about Buzludzha, news that the monument will eventually be transformed into a history museum have been largely well received.
The monument is accessible along a pitted, zigzagging road branching from the E85 between Shipka and Kazanlâk. It's a 30-minute drive from Kazanlâk.