Treasure Island, California

The flat and angular manmade Treasure Island contrasts nicely with the natural and hilly Yerba Buena Island, to which it is connected. 400 acre Treasure Island was created (by dumping dredged material) to house the 1939 Golden Gate International Exhibition, a world's fair that celebrated the joining of the Bay through the recently opened Bay Bridge and Golden Gate Bridge. The site was selected as it was in the middle of the Bay, thus not favoring any city. The Navy took it over soon afterwards christening it Naval Station Treasure Island, and built out the island as a training base, which it used for fifty years. In 1997, the Navy closed the base, selling it to the city of San Francisco for what could eventually amount to $105 million, as part of a major redevelopment project to be overseen by the Treasure Island Development Authority.  Few buildings remain from the World's Fair, but the main pavilion was spared by the Navy, along with a couple of large hangar-like structures. One of the first major reuses of Treasure Island after the Navy moved out was by film, television, and advertising companies, which still occupy the two largest buildings.