Anything to see in Bari! We won't have a car.
Any good local tour guides?
Bari is often used as a the port for embarkation on a cruise to Greece/Turkey. The Crusaders also used in for their forays to the Holy Lands. The 'old town' has a Romanesque catherdral, a basilica, some fine palazzo etc. You might need to be extra careful in some areas, particularly in the evenings. Bari is the most important, and largest city in the region of Puglia. How are you arriving?
While not a starred listing in the Michelin Guide, for anyone who is there for a few hours on a cruise ship, there are several worthwhile things to see in Bari that can be done in half a day: The Old Town can be explored in several hours. Start at the TI on Piazza Aldo Moro, ask them for a map and to draw these onto the map: Basilica di San Nicola is a Michelin recommended attraction and the most noteworthy sight, it's in the heart of Old Town and is 800 years old. Also the Cattedrale and the Castello are worth seeing. And have a meal at Al Sorso Preferito!