Split

Diocletian's Palace is less a single monument than the reason Split exists as a city at all. The Roman emperor Diocletian built it as his retirement residence in the early 4th century, and rather than being abandoned to ruin after the empire's collapse, local residents gradually moved into the fortified structure over the following centuries, building homes, churches, and later shops directly into and around its original Roman walls. Roughly 3,000 people still live inside the palace today, which means walking through it means walking through someone's actual neighborhood — laundry lines above ancient columns, cafés operating out of Roman-era stone — rather than a preserved, roped-off site.

The Cathedral of St. Domnius, at the palace's center, has its own strange twist: it was built around what was originally Diocletian's own mausoleum, meaning a fervently anti-Christian Roman emperor who persecuted Christians during his reign ended up with his tomb converted into one of the oldest Catholic cathedrals still in continuous use anywhere in the world.

Below the palace's ground level, a network of substructures — originally storage and service spaces supporting the emperor's private quarters above — survives largely intact and has become one of Split's more atmospheric attractions, doubling as a filming location for scenes set in Daenerys Targaryen's dragon lair in Game of Thrones.

Split functions as Dalmatia's main transport hub as much as a destination in its own right, with regular ferries and fast catamarans connecting to Hvar, known for its livelier scene and lavender fields; Brač, home to the widely photographed Zlatni Rat beach; and Vis, the most remote and least developed of the three, only opened to general tourism after decades as a closed Yugoslav military base.

Compared to Dubrovnik, Split runs as a genuine working city rather than a preserved-for-tourism old town — busier, less manicured, and with a livelier everyday rhythm — while still holding one of the most unusual living ancient sites in Europe at its core.