By foot from Olbia to Olbia (city)
Olbia cruise port is about 2 kilometers from the city center. It's easily reached on foot. The only road from the port to the city center is the Viale Isola Bianca.
Walk till the intersection at the end of Via Isola Bianca. You pass along the marina and the Archaeological Museum. Then go left and follow the Via Principe Umberto. Soon you'll see a sign for the historic center. The main street is Corso Umberto I.
There is a Tourist Office in Via A. Nanni. You can also reach the Old Town via that road.