Hello all: I just had a last-minute trip in Lisbon, Portugal. Here are some notes:
Lisbon is a hilly city, whose sidewalks are mainly built of cobble stones. Surfaces are often uneven. Be careful if you have mobility issues.
Bolt (ride sharing service) is an alternative to public transit. I used it a lot. A Bolt ride from my hotel (Altis Grand) to the airport cost 10 euros.
Restaurant prices are more affordable than in California. However, OTC med prices aren't (I bought cold/flu meds) for those who don't have local health insurance. In general, it's necessary to book a table at popular restaurants for dinner. For the best food, avoid eateries in the touristy areas.
Many small hotels are not equipped with elevators. Please check before booking a room.
I took a train from the Algarve to Lisbon via Tunes. Neither the local train nor the high speed train was comfortable, but acceptable.
The airport in Lisbon is quite small, compared to those in capital cities. TSA lines are long but there is a Fast Track available to premium class travelers or those who are willing to pay 9 euros. Lounge (at least for non-TAP travelers) access is BEFORE immigration and therefore please allow more time to go to your departure gate, as I heard immigration lines can be long. I flew to another city in the Schengen zone and therefore did not go thru' immigration at Lisbon.