Athens International Airport "Eleftherios Venizelos" (Greek: Διεθνής Αερολιμένας Αθηνών "Ελευθέριος Βενιζέλος", Diethnís Aeroliménas Athinón "Elefthérios Venizélos") (IATA: ATH, ICAO: LGAV), began operation on 29 March 2001 and is the primary civilian airport that serves the city of Athens and the region of Attica. It is Greece's busiest airport and it serves as the hub and main base of Aegean Airlines and its subsidiary Olympic Air as well as other Greek airlines.