In our opinion, Cadiz is very walkable and quite small in scale. Your info desk/concierge on board should have a local map for you to venture forth to the Barrio on your own. We went there on a Voyages to Antiquity cruise and only had a half day in Cadiz. Keeping in mind your sailing time (and arrival time in port), decide if you'll take a panoramic bus ride with Royal Caribbean or if you will venture forth on your own. I'm guessing you won't have time to do both. Cruise ships come in to port near the large plaza (near the Burger King) and it is easy to walk through that plaza and keep walking to the center of Cadiz which is pretty much where the Barrio La Vina is. Although it is very easy to find your way around in Cadiz, none of these neighborhoods are all that well marked or defined. Better to choose an attraction you want to see there in the Barrio and then focus on that location; you'll have an easier time locating the Barrio that way.