The Nine Sisters are a string of hills that partially run through San Luis Obispo. They are geologically noteworthy for being volcanic plugs. The Nine Sisters (sometimes called the Seven Sisters) Morros Morro Rock is in the foreground. The Nine Sisters are, west to east: Morro Rock (no climbing access), Black Hill, Cabrillo Peak, Hollister Peak (no access, private property), Cerro Romauldo (restricted access), Chumash Peak (restricted access), Bishop Peak, Cerro San Luis (San Luis Mountain), Islay Hill.
