Detention center angel island.jpg 720 × 482; 130 KB. Detention Center at Angel Island, an island in San Francisco Bay that offers expansive views of the San Francisco skyline, the Marin County Headlands and Mount Tamalpais LCCN2013634659.tif. Dormitory at Angel Island Immigration Station on Angel Island in San Francisco Bay, California. Location Boston, Massachusetts, United States. CB Rank (Hub) 1,163. Number of Founders 5,383. Average Founded Date Jan 14, 2002. Percentage Acquired 8%. Percentage of Public Organizations 1%. Percentage Non-Profit 4%. Number of For-Profit Companies 6,548. Number of Non-profit Companies 290.