Kansai International Airport (colloquially known as Kankū ) is an international airport located on an artificial island in the middle of Osaka Bay off the Honshu shore, 38 km (24 mi) southwest of Ōsaka Station, located within three municipalities, including Izumisano (north), Sennan (south), and Tajiri (central), in Osaka Prefecture, Japan.
Kansai opened on 4 September 1994 to relieve overcrowding at the original Osaka International Airport, referred to as Itami Airport, which is closer to the city of Osaka and now handles only domestic flights. It consists of two terminals: Terminal 1 and Terminal 2. Terminal 1, designed by Italian architect Renzo Piano, is the longest airport terminal in the world with a length of 1.7 km (1.1 mi).
It is a single four-storey building and has a gross floor space of 296,043 square metres (3,186,580 sq ft). The terminal's roof is shaped like an airfoil. This shape is used to promote air circulation through the building: giant air conditioning ducts blow air upwards at one side of the terminal, circulate the air across the curvature of the ceiling, and collect the air through intakes at the other side.
According to en.wikipedia