The Alcatraz Cruise Night Tour is a must-see. The adventure begins at Alcatraz Landing (Pier 33) where you will board the last boat of the day.
The private guided tour around Alcatraz Island points out the hidden spots used for attempted escapes and prison structures unreachable by foot. In addition, you can tour the Cellhouse on your own with the Doing Time audio.
This Tour is popular, so book tickets within the 90-day window of opportunity. Buy them here.