Treasure Island is an artificial island in San Francisco Bay and a neighborhood of the City of San Francisco. Built 1936–37 for the 1939 Golden Gate International Exposition, the island's World’s Fair site is a California Historical Landmark. Buildings there have been listed on the National Register of Historic Places, and the historical Naval Station Treasure Island and auxiliary air facility (for airships, blimps, dirigibles, planes and seaplanes) are designated in the Geographic Names Information System. - source: Wikipedia