The Diocletian's Palace Basement is among the best-preserved Roman underground structures in the world and a famous Game of Thrones filming location. These interconnected ancient halls mirror the floor plan of the palace above with remarkable precision. Built in the 4th century AD to support the floor of the imperial apartments above and to level the sloping terrain toward the sea. Scenes featuring Daenerys Targaryen and her dragons in the dungeons of Meereen were filmed here. The central hall houses a souvenir market and rotating art exhibitions. Original stone columns, arches, and vaulted ceilings give visitors an authentic experience of Roman architecture preserved for seventeen centuries