The Kansai International Airport in Osaka Bay, Japan is built on the largest man-made island in the world. Discover how engineers built an artificial island on top of a soft clay seabed 65 feet below the bay's surface with 180 million cubic meters of rock and soil. When opened, the one-mile-long terminal was the longest building in the world. The island and terminal must deal with land subsidence and withstand typhoons and earthquakes.