Croatia’s Istrian coast was under Venetian rule for four hundred years, and the Italian influence is still in evidence in picture-perfect towns such as Rovinj: with its cobbled piazzas, Baroque churches and shuttered houses, it’s an almost overwhelmingly pretty place. In the harbour, fishing boats bob alongside swanky mega-yachts, while along the quaysides, sun-shaded café tables blend with the orange tangles of fishermen’s nets.