Tours start at the Torre del Oro by the riverside and complete a circuit around the city taking in both the Expo 29 and the Expo 92 sites
The tours run until relatively late in the evening (6pm in March to 10pm at the height of summer) so you can get several tours in on your 24 hour ticket
There are only four stops on the tour, so they are not so convenient for hopping between attractions, but more for moving between areas where attractions are
In addition to the bus tour the ticket also includes a walking tour around the cathedral area, as this is totally pedestrianised