Treasure Island is a man-made landform in San Francisco Bay and a neighborhood of the City of San Francisco. Built 1936-7 for the 1939 Golden Gate International Exposition, the island's World’s Fair site is a California Historical Landmark with buildings having been listed on the NRHP, and the island's historical naval station and auxiliary air facility (for airships, blimps, dirigibles, planes and seaplanes) are designated in the Geographic Names Information System.

The San Francisco neighborhood that includes Treasure Island extends far into San Francisco Bay and includes a tip of Alameda Island. Yerba Buena and Treasure islands together have a land area of 576.7 acres (233.4 ha) with a 2010 total population of 2,500. Treasure Island and its 900 ft (270 m) causeway total 535 acres (217 ha) connected by roadway (e.g., San Francisco Muni's " 108 Treasure Island") to Yerba Buena Island which has the Transbay Terminal ramps to the middle of Interstate 80's San Francisco–Oakland Bay Bridge. The island has a marina and will have a bikeway connecting to the Eastern span replacement of the San Francisco–Oakland Bay Bridge when it is completed. (more...)