Flights. Lisbon's Humberto Delgado Airport is 7 km from the center and its red metro line starts under Terminal 1, so you can be at a hotel in Baixa-Chiado in under 25 minutes with one change. In the route lists we checked, Lisbon has year-round direct flights to London, Frankfurt, Warsaw and Belgrade. Porto's airport is 11 km out, with metro line E reaching the center in about half an hour. Porto has year-round flights to London, Frankfurt and Warsaw, and its Belgrade route is seasonal. Lisbon is the easier airport to reach, and it's a better choice if you're booking a single return trip. If you're doing both cities, check an open-jaw fare (into one, out of the other) against a return to one airport: it saves the 2 hours 45 minutes back, but it only makes sense when the price difference is smaller than a one-way train ticket, which is about 10 EUR if you book ahead and 35.70 EUR at the full fare. Which end first is mostly a matter of fares, and the direction suits either: Lisbon first and Porto last ends the trip on port wine, and Porto first lets you finish with Lisbon's nightlife and the capital's longer list of flights home.
Entry. Portugal is in the Schengen area, so UK, US and Serbian citizens can visit without a visa for up to 90 days in any 180. The EU's Entry/Exit System began registering non-EU visitors with a photo and fingerprints at the border in October 2025 and has been fully operational since 10 April 2026, so allow extra time at both airports. The ETIAS pre-travel authorization isn't running yet and has no confirmed start date (an earlier target of late 2026 has been dropped), so check the official Travel to Europe site before you book.
Around town. Both are easy without a car. Lisbon has the metro, trams, buses and suburban trains on one rechargeable Navegante card. Porto has a metro that reaches Casa da Música, Serralves, Matosinhos and the airport, and its trains to the Douro leave from Campanhã, not São Bento. Don't hire a car in either city.
Safety. Both are ordinary, safe European cities for visitors. The UK Foreign Office names pickpocketing in busy tourist areas as the main nuisance and wildfire (April to October) as the main natural risk, and the EHIC and GHIC cover state healthcare (advice). Keep an eye on your bag in the Lisbon crowds and in Porto's Ribeira.
Between the two. The Alfa Pendular fast train takes under three hours, roughly 2 hours 45 minutes (seat61 lists the timetable and fares), from Lisbon's Santa Apolónia or Oriente to Porto's Campanhã station. The full second-class fare in 2026 is 35.70 EUR (49.90 EUR in first class), and advance fares are much lower, from about 10 EUR, so book on the CP site a few weeks ahead. Slower Intercidades trains also run on the same line.