What are possible day trips from Portugal?
Thanks

From Lisbon? Sintra, the Palacio da Pena, the Moorish castle, a wander thru the enormous park surrounding them. Pack a ruck with a bottle of vinho verde and a picnic lunch - there are some lovely spots in that park. It's worth a full day.

Sintra is great and definitely worth a day. I think you can also take a bus to Evora, and maybe even Obidos (although not the same day - they are in opposite directions.

From Portugal or from Lisbon?

Yes, I meant from Lisbon.
Thanks

It is very easy to make day trips by train: there are 2-3 trains per hour. They are clean and very cheap.

Sintra - we saw there the town, National City Palace, Pena Palace. There are also 2 more other palaces, but we had not enough time in the same day for all four.

On the line Sintra-Lisbon is Queluz with its splendid palace and one of the most beautiful garden that we saw, full of statues, fountains and flowers.

Cascais and Estoril - see the towns, casino , beaches.