Is Lisbon actually worth leaving the airport for on a layover?

Lisbon can be worth it, but only when you treat the layover like a single focused outing instead of a checklist sprint.

The question is less “can you leave?” and more whether security queue variability is likely to destroy the return margin on the day you travel.

I usually want one signature food stop or one neighborhood walk, then I head back much earlier than feels necessary.

If your tolerance for uncertainty is low, staying inside Lisbon Airport may honestly be the better trip decision.