Our guide, Nicholas, gave a fantastic tour of Bari. It was informative and personable. We passed through a few larger tour groups during our walk, and I felt like we were having a better experience than they were. He was completely fluent in English, which was perfect for two dumb American college students who had little to no grasp on the local language. Some advice for other travelers, we were three young men in our twenties, walking fast and far, and we got the full tour of Old Town, The Beach Front, and a considerable hike (at least 45 minutes, probably an hour) from our AirBnB done within 3.5 hours. Take that information how you will, but I can't imagine needing more than 4 hours for an extensive tour of Bari. I can't stress enough that this tour was of high quality, given by a professional in his trade, and on top of that we booked it last minute (within 36 hours, and I can't imagine that Nicholas had more than 24 to prepare). Highly impressed. Full recommended.