One of the most popular tours in Rosario is a visit to the islands across the river from Río Paraná. Getting to the river islands is definitely a little easier with some help. Cabañas del Francés (Tel: 03414492995) run an ecotourism operation around the islands and also have little river-side cabañas to stay in if so desired. The day trips are definitely worth checking out. They will pick you up from Muelle de Costa Alta, north of town in front of the Rosario Victoria bridge, provide transportation to the island and back, prepare a delicious Argentine style BBQ, including salad and lemonade, and give you access to all of their facilities, including kayaks, volleyball nets, bathrooms, the bar, a restaurant and beaches. If you are really lucky the local kids can show you the best place to take the 20ft plunge off the dock into the river.
For a guided tour of the city by bus check out Rosario Vision (Tel: 034-¡1156433857). Their open air "topless" buses do tours of both the river coast and places of historical significance. Tours are provided in English, Portuguese and Spanish. The tour costs $7.