To Be Determined: Transfer from Airport
Split has one main airport, Split Airport, also known as Resnik Airport. Taxis are available directly at the terminal exit, or you can arrange a private transfer for added convenience. UberX is also available in Split for those with the mobile app. It will cost about 250 HRK to reach the city by car. Keep in mind that if staying in Old Town, your driver will likely need to drop you off near your hotel as cars are not allowed in the pedestrian zones. If you need help with your bags, you should arrange it beforehand with your hotel or a private transfer.
If you want to save money, there is a direct shuttle bus line for 35 HRK which departs from in front of the terminal and drops off at the Split bus station, from where it is a relatively short walk to the historic center of Split. If you really want to save money, the public bus line no. 38 picks up near the airport as well, but of course you'll need to make a lot of stops along the way and it may not be the most convenient way to travel if you have bags.
Mid-Day/Afternoon: Diocletian's Palace
Split's Old Town started out as a luxurious retirement palace for the Roman Emperor Diocletian. As Roman emperors often met bloody ends, about half of the palace consisted of a less luxurious fortress designed to accommodate a large garrison of loyal Roman soldiers. Within the palace's high walls there were also temples, streets, and large courtyards, meaning it was only natural that long after the Diocletian was gone and the empire fallen, much of the palace was incorporated into Split's Old Town. Indeed about half of the Old Town consists of the former palace area.
Despite falling into disrepair and constant reconstructions over the intervening millennia, the Palace remains one of the best-preserved examples of Roman architecture in the world. It's principal set-piece buildings, such as Diocletian's mausoleum and the Temple of Jupiter still remain. But the palace is far from being just an archeological site and it continues to this day as a living and breathing historical monument with 2,000 to 3,000 people still resident within its ancient walls. This means that so much tinkering has gone on over the centuries that it's no longer immediately recognizable as an ancient Roman structure. On the other hand, up close and personal you can still make out the remains of some of the imperial apartments that are used today as outdoor bars and cafes and shops. And the medieval tenements built by the Venetians were built in large part from the stones scavenged from Diocletian's original buildings.
The tangled mass of alleyways, small squares, and narrow lanes just outside the Palace is also well worth exploring. The Venetian architecture makes the setting particularly enchanting (Split was ruled by the Republic of Venice for centuries).
Peristyle
See the beautiful courtyard which was once the center of the palace, and is now the heart of Split.
The Peristyle was the central courtyard of the palace complex and the crossing point of its main streets. The columns around the courtyard were pillaged from Egypt, though the officer in charge of the operation must have forgotten to get some extras as four of the columns are clearly different from the others. There's also a black granite Egyptian sphinx on one side dating from 1500 BC which originally flanked the entrance to Diocletian's mausoleum (other sphinxes around the palace were decapitated by Diocletian to allay his superstition that they posed a threat to his rule). If you sit on one of the red cushions scattered around the Peristyle you'll be approached by a waiter with a menu of very expensive drinks, but it may be worth it just to sit and lap up the history and watch people go by.
At the southern end of the Peristyle, steps lead up to a cone-shaped, roofless chamber which once served as the palace vestibule. Visitors would wait here before being summoned before the ex-emperor into his private apartments.
Riva
Take in the scene on Split's swanky seaside promenade.
Along the exterior face of the former palace and down the length of the Old Town runs the wide and breezy Riva, the principal sea-side promenade in central Split. Lined by palm trees, restaurants, and cafes, it gets wildly busy on summer evenings. It is the perfect place to relax, take in the scene, and watch people and boats pass by.
St Domnius
See how the mausoleum of an emperor who persecuted Christians was converted into a stunning medieval church.
Looming over the Peristyle and over all of Old Split for that matter is the belfry of the Cathedral of St Domnius. The dome of the church was originally Diocletian's mausoleum. Diocletian's body disappeared 170 years after internment and nobody knows where. Ironically though, the church does hold the bones of St. Anastiasius, a saint killed by order of Diocletian. Indeed, the altar which holds his relics is the finest in the church, and the sarcophagus contains a fascinating relief called The Flagellation of Christ.
The cathedral also houses a treasury full of monstrances and fascinating reliquaries in the shape of heads containing relics in small transparent lockets encased in the forehead. Another highlight is the walnut-and-oak main entrance doors with an inspired comic-strip-style sequence showing 28 scenes from the life of Christ. The bell tower started in the 13th century and not completed until 1908 is definitely worth climbing up for the panoramic view over the city, though it is quite steep.
Bronze Gate and Palace Cellars
Enter this ancient gateway to discover palace cellars used as film sets for Game of Thrones.
While today about 200 feet (60m) from the water, the Bronze Gate originally sat directly on the sea, allowing boats to pull directly up to the palace. As you enter the gate you will find a mass of souvenir and arts & crafts stalls, but just inside the entrance on either side are the substructures, or cellars of the palace. After the palace fell into disrepair, the cellars were used as rubbish pits. Families occupying the apartments above would simply create holes in the floor and voila, they had an instant trash dump with a seemingly unending supply of space. Of course centuries of trash did eventually them fill up and they were only rediscovered in 1956; the excavations continue to this very day.
While entrance to the cellar is not free, it provides an excellent idea of what the palace must originally have looked like, as they're an exact mirror image of the imperial living quarters above. Game of Thrones fans will also be happy to learn that the cellar was used as a filming set, including as Daenerys Targaryen's grand Meereen throne room.
Fish market & Marmontova Street
Join the locals at Split's main fish market.
This is a genuine fish market rather than a set piece for tourists. So it is a bit smelly and bloody, just like a real fish market should be. If you want fresh fish and seafood, its the best place to go in Split. There is a bit of a frenzy in the morning when the fresh catch is brought in, so that is the most intersting time to visit.
If you aren't in the market for raw seafood, on the adjacent Marmontova street you'll find take out places where you can get cooked seafood to go. This elegant pedestrian street is also lined by high-end shops, and is definitely worth a stroll.
Late Afternoon: Fishermen's Quarter
Veli Varoš is a neighborhood situated at the western end of the old town that is crammed full of charming old stone houses and apartments characteristic of Dalmatia, and narrow cobbled streets that wind up the Marjan Hill. The district once represented the poorer part of Split developed by farmers and fishermen looking to make a better living in the city and seeking shelter from Ottoman military incursions. Today property prices have accelerated northwards, but it's still well worth reconnoitering the maze of paths and traffic-free lanes as you head to the top of the neighborhood to catch magical views of the city. Venture beyond the Fisherman's Quarter and you will be surrounded by typically Mediterranean forest landscape on the Marjan Peninsula.
Vidilica Terrace
Walk up to this terrace for the best view of Split.
No terrace offers a better view than this, the whole of Split laid out before you - and islands beyond. There is a nearby cafe and bar which contains blown-up sepia postcards of pre-war Split scenes. Most visitors, however, try to find an outside table, the children kept safe within the stone wall guarding the steep drop. The grounds behind the cafe contain Split's old Jewish cemetery.
Mestrovic Gallery
Hike the Marjan Peninsula to reach the seaside villa of 20th-century sculptor Ivan Meštrović.
Many consider Ivan Meštrovič to be greatest sculptor of religious subjects since the Renaissance. The Meštrovič Gallery is located in an ostentatiously palatial building that Meštrovič himself planned as his home and studio. Fronted by a veranda supported by Ionic columns, the house was completed in 1939, giving Meštrovič just two years to live in it before fleeing to Zagreb to escape the Italian occupation. The gallery is also a wonderful sanctuary away from the hubbub of the city with wonderfully romantic views of the Adriatic. Even if you're not interested in religious sculptures (they're not all religious) the gallery still contains a highly impressive collection of art.