
For guests who stay a bit longer at the apartment, and who ask me about other things to see besides Lisbon, I usually recommend one day out in Porto, or "Oporto", as said in English. Porto is Portugal's second largest city, known among us as the "capital do Norte", and is the home of the famous Port wine. The city itself is quite different from Lisboa, as the the Tejo and the Douro are different, too. While Lisbon spreads lazily out along the Tejo, Porto is a clutch of houses perched over the Douro. While Lisbon is bright and shiny, Porto is dark, cold (try ot out in Winter! :-) ). Both cities have their own kind of unique beauty.
Looking it up in the map, the 320 kms separating both cities seem quite a distance, but in reality are not. The Alfa trains cover the distance in just under three hours, and leave regularly from Santa Apolónia station, just 10 minutes walking from home. Catching the 8:00 train, for instance, would put you there before 11:00, but trains start leaving at 6:00, plenty to choose from.
Prices range from 19,50 euros (for Intercidades trains, trips taking 15 min more) to 27,50 euros (for Alfa trains), each way. Prices and timetables can be checked at CP, the Portuguese train company, access it's website here. For some suggestions on what to do and see, ask me, I have my own routines up there, and quite enjoy the city :-)