High Quality Content by WIKIPEDIA articles! Treasure Island is an artificial island in the San Francisco Bay between San Francisco and Oakland, and an emerging neighborhood of San Francisco. The island is entirely within the City and County of San Francisco, whose territory extends far into San Francisco Bay and includes a tip of Alameda Island. Treasure Island is connected by a small isthmus to Yerba Buena Island. According to the United States Census Bureau, Yerba Buena Island and Treasure Island together have a land area of 2.334 km2 (0.901 sq mi) with a total population of 2,500 as of the 2010 census. The island is named after the novel Treasure Island, by Robert Louis Stevenson, who lived in San Francisco from 1879 to 1880.