eight days in late March -- should I skip the Algarve

You don’t have time for the Algarve since you need five nights for Lisbon/Sintra and two for Porto. The Algarve is worth three nights during the summer but not in Mar.

Don’t even think about it! You barely have time for Lisbon and Porto. Also, be aware that Easter is 31 March and Portugal gets quite crowded the week before and after Easter. If you are coming in that time frame, reserve well ahead.

Btw - there are nice beaches close to Lisbon - both in Cascais and Sintra. And, it’s possible the weather would be ok for the beach, as long as you didn’t plan to get in the water.

We spent 8 full days in October in Lisbon/Sintra/Porto (flew out on the 9th day). I think 8 days in Lisbon/Sintra/Porto is a full schedule and you shouldn't add any more places, unless you're the kind of traveller that likes to just hit the main sights and don't also enjoy poking here and there to see what you discover.

Husband and I aren't the kind who just like to hit the main sights. In fact, we usually hate that kind of tourism. We like to both hit the main sights and also have time to mosey and explore the main sights more in depth and linger around for other things as they arise including simple things like, for example, enjoying time in a pasteria, popping in to have an espresso and a new snack we see "calling" us from a window, seeing an interesting museum and popping in, deciding why no try to ride a tram line from end to end, etc. Did I say how much we hate the kind of tourism that is just about hitting main sights? ;-)

Anyhow, we found that 8 days were not enough for Lisbon/Sintra/Porto. Our schedule was 4.5 days in Lisbon, 1 day in Sintra, 2.5 days in Porto. We could have spent another 5 days in Lisbon, another extra day in Sintra, and at least another 3 to 4 in Porto.

I have never been to the Algarve, but from what I read, if you aren't really beach people and don't have that much time, skip the Algarve. Husband and I aren't beach people. Yes, we enjoy walking on the beach but we don't like sun tanning, we don't lay around on the beach, etc. We skipped the Algarve this time.

Interestingly, the number of people whom I know have been to Lisbon say 3 days is enough. I have no idea what they're thinking and clearly they don't travel like we do. We could have easily done 9 days alone in Lisbon and just enjoyed exploring everything and walked everywhere and come out feeling like we had an awesome time in Lisbon.

We did nine days in Lisbon on our first trip to Portugal. There is so much to see and do there. Then we rented a car and out to see the rest of the country..