Split

History and sights:
Split on the Zalanski Zaljev was founded in the as the Greek colony Spálathos.
The settlement took place from Vis, which since 367 BC had gained autonomy from the mother city Syracuse, and now founded its own colonies.
In the north of the city is the Roman settlement of Salona. The most important building there is the Arena, now destroyed.
The Diocletian Palace was built by Emperor Diocletian from 295 to 305 AD. After his death, the Roman Empire used the palace as an administrative headquarters, barracks, and the residential wing served as a residence for various emperors.
With the decline of the Roman Empire, the palace also fell into disrepair.
In the early 7th century, Avars and Slavs destroyed the city of Salona. The surviving Salonitans found refuge in Spalatum's palace in Split and turned the palace complex into a city. Today, the former palace still forms the eastern part of the old town of Split and with shops, markets, squares and the Cathedral of St. Domnius, which in ancient times was the mausoleum of the imperial couple Diocletian and Prisca and formed the center of the palace.
After the Peace of Aachen (812), Spalatum and Split belonged to Byzantium. In 1242 the Tartars advanced to the gates, but Spalato held out and granted refuge within its walls to the defeated King Béla IV of Hungary and Croatia, Dalmatia and Rama. The further history of the city would go beyond the scope here.

The most important sights is the Diocletian's Palace (4th century), is since 1979 UNESCO World Heritage Site and today part of the Split Old Town. After the Roman period, the complex was transformed into an inhabited fortress, which changed over the years due to cultural influences.
On an exploratory tour of Diocletian's Palace, there is much to discover, such as. the Peristyle, the Podrumi, the Cathedral Sveti Duje and the Vestibule.
Peristyle: A real highlight of the city and and the central square of Diocletian's Palace. In the past, this place was a kind of reception hall for imperial visits.
Vestibule: In Diocletian's Palace it was once the anteroom to the imperial apartments, which unfortunately are no longer preserved. 
Podrumi: The cellars of Diocletian's Palace are one of the best preserved ancient building complexes in the world.
The Golden Gate in Split was called Porta Septemtrionalis in Roman times and was renamed Porta Aurea "Golden Gate" only during the Venetian rule in the 16th century. It is the most magnificent and beautiful of the four palace gates.
After Diocletian's Palace, the Cathedral of Domnius (Sveti Duje) is another must-see on the city tour. Once this church was the mausoleum of the Roman emperor Diocletian and his wife Prisca. Today it is considered the oldest Catholic cathedral in the world.
Also the bell tower with over 200 steps should not be missed, because view over the city is  spectacular.