June the 23rd, 2025 – Croatia is the country that just keeps on giving when it comes to archaeological finds. A secret tunnel has just been discovered under Diocletian’s Palace in the very heart of Split.
As Morski writes, during the renovation of Hrvojeva Ulica in Split, a guard passage from antiquity was accidentally stumbled upon. It had remained buried for at least 500 years. It connects the street with Diocletian’s cellars. Each new discovery sheds new light on the rhythm of life in the palace, and these secret tunnel right underneath Diocletian’s Palace writes yet another chapter in the endless history of Dalmatia’s capital.
Those working were looking for a tower demolished during the 17th century. Instead, they came upon a door to a secret underground tunnel beneath Diocletian’s Palace. It was buried in the eastern rampart around 500 years ago, when the ancient towers were collapsing and the walls were thickened up before the Ottoman invasion.
It’s pitch black in the cellars on the other side of the walls, with only the occasional pigeon making a characteristic coo. That’s the present day. If we hop in our time machine and head back to the time of the Roman Emperor Diocletian, it was very busy here.
“We’re slowly but surely discovering every inch of Diocletian’s Palace, the original walls, as you can see, and this ancient staircase that led outside. It all tells us a lot about how everyday, practical life within the palace functioned. It also weaves stories about the construction of the palace itself,” Vesna Bulić Baketić, director of the Split City Museum, told HRT.
Archaeologists are currently investigating in this location for the reconstruction of the palace vaults and the renovation of Hrvojeva Ulica.
“For years now, we’ve been investing in the renovation of the perimeter walls of Diocletian’s Palace, as well as its other remains. Of course, the arrangement of the eastern wall itself showed the need for a broader investigation of the southern rectangular tower,” explained Jasna Jerkov, head of the Department for the Old City Core and Heritage.
The foundations or remains of Diocletian’s Tower, later owned by the nobleman Ciprianis, haven’t yet been found. As things currently stand, it’s like it totally disappeared. Until something is found, it’s up to the archaeologists themselves to at least investigate what the secret tunnel underneath Diocletian’s Palace was used for and who was it used for, both during Roman rule and later on.
“It served as an entrance to the tower, but it connected Diocletian’s cellars with stairs, and with stairs that led to the upper floors with Diocletian’s apartment itself. What we do know is that the bishop moved into the emperor’s apartment and a diocese was formed in the eastern part of the emperor’s apartment. This eastern part was the bishop’s garden,” revealed the head of archaeological research, Nebojša Cingeli.
The palace’s cellars have one entrance and one exit. That makes the discovery of this incredible secret tunnel under Diocletian’s Palace even more stunning. For the safety of visitors, and as an interesting plot in the long, rich story of Split, it will remain open – forever.
