Split

Split is the one that surprised me most. The old town isn't near a Roman palace, it IS one - Diocletian built it to retire into and people simply never left, so there are flats and bars and washing lines built into fourth-century walls. Go and stand under the vestibule and look straight up: an open circle in the brick dome with the sky through it, and usually someone singing klapa underneath because the acoustics are ridiculous. Get lost in the lanes, come out on the Riva for a coffee and watch the ferries. Wonderful place.