City and County of San Francisco, and are considered part of Supervisorial District One (Northwest), also called Richmond District. South Farallon Islands Southeast Farallon Island (SEFI) is the largest island, with an area of 95.79 acres or , and is the only inhabited one. The island is pyramidal in shape and high. The peak, Tower Hill (actually a double peak consisting of Lighthouse Hill and Little Lighthouse Hill), is the location of a lighthouse, the Farallon Island Light. The large flat area in the southeast of the island is called Marine Terrace. Immediately south of it is Mussel Flat, about by , which is cut off from the main island only during high tide. Seal Rock (Saddle Rock), about south of SEFI, is about by in size and high. Maintop Island (West End) is immediately to the west of SEFI, separated by a narrow impassable gorge, The Jordan (Jordan Channel), which connects Mirounga Bay in the south to Maintop Bay in the north. It is the second largest island, and high at Main Top hill in its eastern part. The Great West Arch, or Aulon Arch, is a rock formation in the west of the island, and Indian Head is in the south. The Drunk Uncle Islets are a group of small rocks just northwest of Maintop Island. Aulon Island and smaller Great Arch Rock (Arch Rock) are immediately north of the northern tip of SEFI, and together about by in size. They are barely separated by a narrow gorge. Great Arch Rock is not to be confused with Great West Arch, a rock formation in the west of Maintop Island. Sugarloaf Island (usually just referred to as Sugarloaf) is northeast of Great Arch Rock, and just slightly larger in size, with a height of . Southwest of Aulon Island, Great Arch Rock and Sugarloaf Island, and in the northeast of SEFI, is protected Fisherman Bay. Sea Lion Rock is just northwest of Aulon Island, diameter approximately . Hurst Shoal is located about one kilometer southeast of the southeastern corner of SEFI. It has a least depth of . Middle Farallon Island Middle Farallon Island, northwest of SEFI, is a high guano-covered black rock about 65 meters in diameter, with an area of 3,362 m2. This island is informally known as "the pimple." North Farallon Islands North Farallon Islands, about 7 km further northwest, consist of two clusters of bare