Labyrinth of Buda Castle

The caves beneath Castle Hill formed naturally through thermal spring activity over thousands of years, part of the same geological system that also produces Budapest's thermal baths. Since medieval times, sections of this cave network were adapted for human use — as storage cellars (particularly for wine, given the constant cool temperature), and at various points as shelters and even, according to some accounts, as a temporary prison holding figures including Vlad the Impaler (Dracula), whose imprisonment in Hungary in the 15th century is well documented, even if the specific cave connection is more folklore than confirmed fact.

During WWII, sections of the labyrinth were reinforced and used as air-raid shelters and briefly as a military hospital during the brutal 1944-45 Siege of Budapest, predating the more famous Hospital in the Rock in a separate section of the same broader cave system beneath Castle Hill.