Itinerary feedback for 12 days in Portugal without a car

Not having a car in Lagos and Obidos will be a challenge. There are buses but they aren’t very often.

Driving in the Algarve and central Portugal is quite easy. That said, with your short length of time in the country, I wouldn’t trek to the Algarve. Central Portugal is much more authentic and there are lovely beaches. Nazaré isn’t my favorite unless you are there for the monster waves - which just happen in winter.

The Algarve is much easier with a car, but with your timescale, I too would stay north and drop the Algarve. Lagos to Evora involves 3 trains and will take around 6 hours plus door to door, as you almost have to return to Lisbon before heading south. Driving this route is quicker. I would opt for Porto over the Algarve unless you want beaches.

Two nights in Evora is a sensible amount of time there.

Obidos is worth a couple of hours, but wouldn’t be my choice if a base - I would opt for Caldas da Rainha, Alcobaca or Tomar. Getting around by bus will take in many cases about double the length of time as driving, so you may want to consider hiring a car. Driving is easy other than in busy Lisbon.

Thank you everyone. Any suggestions for a home base to explore central Portugal without a car that doesn’t require relying on limited and long public transportation?

I haven't been to Portugal recently at all, but what I did was take a one-day bus tour that hit three or four small towns I was interested in. I know Alcobaca and Batalha were included. I see online that such tours are still offered from Lisbon. They may include one or more of Obidos, Tomar and Fatima in addition to Alcobaca and Batalha.

I am not a big fan of such tours, but sometimes they are the only practical way to get to multiple small towns in one day. It's important, though, to be sure you'll have a reasonable amount of time at stops where you have specific sightseeing objectives. If you have a deep interest in a specific sight or museum, it may be better to devote the time necessary to travel there on your own by public transportation rather than squeezing everything into a 1-hour tour stop.

This map https://portugal4me.wordpress.com/2016/05/22/detailed-rail-map-of-portugal/ was the most detailed I found on all the smaller regional stops. It helps you see which connections are feasible or not. However, some are actually easier than it looks such as direct trains from Lisbon to Evora or direct from Lisbon to Tomar. Some stops with town names are misleading because the train station is far from the town.

Sintra is much better as a 1-2 night stay. STart the trip there. Take Uber or taxi from LIS. 2N would be better. Then take the train or save time and Uber to Lisboa-Oriente for a train to Evora (if that's a priority), then train (probably via Lisbon) to Coimbra-B for 1-2 nights (taxi/uber to/from station). Then train to Porto-Companha and taxi to/frrom the center - Uber's a problem at Companha and taxis are almost as cheap. In Porto you can take day trips to the Douro Valley (maybe river cruise) and/or Aveiro. Back to Lisbon by train. Use the official site fro train schedules.