As you visit Lisbon you will for sure want to experience Lisbon in an authentic way, and one of the coolest and nicest ways to see and feel Lisbon is by riding on one of the one wagon tram lines. The most famous tram line is number 28 which travels between Praça Martim Moniz, Chiado and Campo de Ourique.
Often tram 28 is packed with people and that might not so nice, especially since you keep paying attention to your valuables, since a packed tram is a very popular place to go for pickpockets. That is why you should just walk around, and as you see a tram 28 with free space and seats, jump in and enjoy the ride. You can buy a ticket from the driver, or if you have a 24 hour Lisbon public transportation ticket you can use that as well.
Tram line 28 is an attraction in itself, and you will also get to see famous attractions along the way as the SA Cathedral. Just after the cathedral you can also enjoy a beautiful viewpoint towards the Tagus river, and from there you can easily walk towards the entrance of the castle, one of the most famous and popular attractions in Lisbon.
If you see it, then tram line 25 is also very nice, and is worth a ride as well! There are also some trams with red or green colors. These are special trams made available to those with special tickets, so if you do not want to use a fortune on these, just travel with the traditional trams, and then first and foremost tram line number 28.