We bought 48 hours by bus and tram. 24 hours had been plenty when we were there on 25/4 and neither the tram nor the Belem route ran.
We were not told that at the time of purchase and it is a clear shortcoming.
In the case of the purchase, which was made online, it is further stated that nothing other than the digital ticket is subsequently required.
That doesn't fit either.
When we got on board, the ticket was converted to a printed ticket and that was the valid one afterwards.
We found seats on the upper deck and equipped with a pair of very cheap headsets, we found out how it worked.
The one outlet just didn't!!
So when a couple of other seats became available, we moved and thus both got a bit of noise in our ears.
It is very difficult to hear what is being said and much is irrelevant information about Lisbon in general, "as a nice holiday town".
With that said, you get around important attractions, at least on the Belem tour.
The fact that there are so many people at the various stops is not Yellowbus's fault.
The tour called "Modern Lisbon" goes to the impressive Vasco da Gama tower, which is definitely worth a visit.
Otherwise, most of the trip doesn't matter. In particular, the return journey is directly into the city through suburban neighborhoods and run-down industry.
So if you have the opportunity, take the train/metro directly to the tower and save on the trip by bus.
We didn't get to ride the tram, which is a bit of a shame.
Meeeen, there are quite a lot of people with us all the time, so the question is whether we would have chosen it even if we had the option.
So take the Belem tour, be prepared for LOTS of people at the attractions and it can be difficult to get a seat on the bus.
Good trip