Yerba Buena Island sits in San Francisco Bay within the borders of the City and County of San Francisco. The Yerba Buena Tunnel runs through its center and connects the western and eastern spans of the San Francisco–Oakland Bay Bridge, linking the city with Oakland, California. Treasure Island is connected by a causeway to Yerba Buena Island. According to the United States Census Bureau, Yerba Buena Island and Treasure Island together have a land area of 0.901 square miles (2.33 km2) with a total population of 2,500 as of the 2010 census.

Alcatraz Island is a small island 1.25 miles (2.01 km) offshore from San Francisco, California, United States. The island was developed in the mid-19th century with facilities for a lighthouse, a military fortification, and a military prison. In 1934, the island was converted into a federal prison, Alcatraz Federal Penitentiary. The strong currents around the island and cold water temperatures made escape nearly impossible, and the prison became one of the most notorious in American history. The prison closed in 1963, and the island is now a major tourist attraction.