Which is the longest building in the world?

Kansai International Airport in Japan which is 1700 metres long is the longest building in the world. In the ’60s, when the Kansai region was rapidly losing trade to Tokyo, planners proposed a new airport near Kobe and Osaka. Osaka International Airport, located in the densely-populated suburbs of Itami and Toyonaka, was surrounded by buildings; it could not be expanded, and many of its neighbours had filed complaints because of noise pollution.