Athens International Airport Eleftherios Venizelos, commonly initialised as AIA, is the largest international airport in Greece, serving the city of Athens and region of Attica. It began operation on 28 March 2001 and is the main base of Aegean Airlines, as well as other smaller Greek airlines. It replaced the old Ellinikon International Airport. Athens International Airport is currently a member of Group 1 of Airports Council International.