I've just read this: https://en.wikipedia.org/wiki/Church_of_St._Donatus and there are no notes about pre-Roman ie iron age archaeology.
The church looks stunning and the acoustics will probably be amazing.
It is fascinating that Italy and Croatia have more in common than a nearby Italian neighbor with a shared common language and a long border, such as Switzerland.
Additionally, Italy shares two languages with Switzerland, given the mountain area shared between Switzerland, Austria and Italy, where German is also an official language.
It was the mountains that rise beyond the coast that were the real obstacle. Even in the 21st century, it takes a lot of money and upkeep to make them passable for modern transport.
The projected Beograd-Bar highway slightly south of Croatia is basically a white elephant project.
The Roman amphitheater of Pula, Croatia, likewise, frequently hosts concerts.