It cannot have an expiration date within 6 months of the day you leave for Portugal.
You're going to want some cash in your pocket because there may be places that you want to stop at that only take cash. Use multibanco atm's.
It's easy but the toll roads and parking can get expensive.
You're more likely to find free parking and avoid tolls when you travel slow and small.
Stop in the small towns and find hidden gems along the way.
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Read over 20+ tips to help you plan your next trip to Portugal.