Francisco Sá Carneiro Airport (OPO) is the main international airport serving Porto in northern Portugal, located about 11 km from the city center. Opened in 1945 and later modernized, the airport is named after Portuguese politician Francisco Sá Carneiro. It is the second-busiest airport in Portugal after Lisbon Airport and is known for its modern facilities and efficient service, handling millions of passengers each year with many European connections, especially through airlines like Ryanair.