In December we are visiting family in Portugal and we know that some of the cities and countryside is stunning, so why not add a rail trip to the visit. We've seen the rail map of Portugal but of course that only shows where the track is, does anyone on the forum have actual experience of rail in Portugal that they could recommend?
ps: the search facility on this forum doesn't work on my computer so have to ask
If you're looking for scenery, go to Porto and take the line through the Douro Valley to Pocinho. Stunning scenery, but don't expect any amenities on the train itself - it's a no-frills DMU.
Intercity rail service is comfortable, inexpensive (book online well in advance for the cheapest fares), and reasonably quick, although in some cases buses are more frequent. Consider the Alfa Pendular service on the Porto-Coimbra-Lisbon-Faro trunk. Upgrades to first class are sometimes only a few euros - well worth it.
Lisbon and Porto both have interesting transit systems, including old streetcars. There's also a streetcar line, on a very limited schedule, between Sintra and the waterfront.
Have a great time!