re: Portugal in mid March for 8 days

We only did a couple of days in Porto to see the city and do port lodge tours, so we missed out on the Duoro Valley. Kicking myself for skipping that, but I guess there's always next time. I would highly recommend doing the port tour at Graham's. Spring for one of their "Super Premium" tastings, as it is not much more expensive than their regular tour + tasting and the quality increase exponentially. They have a restaurant on site called Vinum that is great for lunch after you get drunk at a mid morning tasting.

A couple of things worth seeing that are in between Porto and Lisbon are the University and Joanina Library in Coimbra and the Templar Castle in Tomar.

Sintra is a place that definitely deserves a couple of days. Quinta de Regaleira, the Moorish Castle, Pena Palace, and Monserrate Palace are all must-see in my opinion. Tivoli Palace is a really cool hotel there.

It's hard to go wrong in Lisbon, but I would mention that Pasteis de Belem is a must visit for pastries and is right down the street from Jeronimos Monastery. It will likely be packed, but the line moves fast. I would also note that the Santa Justa Lift is dumb and a complete waste of time if there is a line. If it's not crowded then it could be convenient. There's a cool archaeological museum where it drops you off up top if you do decide to ride it.