Alcatraz Island was first a strategic light house and military fort before becoming the infamous penitentiary it is known for today. National Parks Services (NPS) administers the site today.
Catch a ferry ride from the Embarcadero between Fisherman's Wharf and the San Francisco-Oakland Bay Bridge. Reservation made in advance are strongly recommended.
Check out the NPS site for more info => http://www.nps.gov/alca/index.htm
Check out the Triplogs.
This hike is listed as One-Way.
When hiking several trails on a single "hike", log it with a generic name that describes the hike. Then link the trails traveled, check out the example.