Salona Archaeological Site

The amphitheatre at the western end held up to seventeen thousand, and the town behind it may have carried sixty thousand people at its height, which made it on…The amphitheatre at the western end held up to seventeen thousand, and the town behind it may have carried sixty thousand people at its height, which made it one of the larger places in the empire. The outline of the walls and their towers is still readable on the ground, along with the forum, the theatre, the baths and the basilicas.

Avars and Slavs destroyed it in 614, and those who fled went down the road to shelter inside the emperor's retirement compound. Walking the two in that order, the ruins first and the palace afterwards, puts the founding story the right way round.