Jamie Palliser
Google
A 20 minute walk along the riverside from the central Porto area, or alternatively you can take the historic tram (any tram ticket gets 30% off the entry fee).
This building is very impressive, being the old power station used to provide electricity to the trams. Inside there is a large collection of their vehicles through the years, showing how they evolved, all are very well preserved and have interesting information about them - in English and Portuguese.
There is also access to the old power station side, where the generators, transformers, and other equipment needed are still present. Interesting to read about how this came about and was used.
Overall worth a visit, especially paired with the walk or tram ride