My travel buddy and I bought the 24-hour public transportation pass for Lisbon for one of the three full days we were in the city. We used the pass to take the #15 tram out to Belem and back into the city. Then we took the #28 tram from the west-side starting point at the Cemetery of 'Pleasures' (Cemitério dos Prazeres) and rode it until we were told to get off. It was getting dark at this time, so the tram wasn't very crowded with tourists. We really wanted to watch the tram driver and feel what it was like to go up and down the steep hills. I had also read that the tram driver will sometimes stop and get out to assess a particular situation. This was the case when our tram driver had to see if she'd be able to pass a parked car with a large ladder or something on the top of it, and it was almost impossible to pass. We were also able to use the same ticket to take a ride in the Santa Justa Lift (the Eiffel Elevator). I recommend this trip to anyone interested in historic public transportation options. It was really interesting!