Alcatraz Island offers a close-up look at the site of the first lighthouse and US built fort on the West Coast, the infamous federal penitentiary long off-limits to the public, and the 18 month occupation by Indians of All Tribes which saved the tribes. Rich in history, there is also a natural side to the Rock—gardens, tide pools, bird colonies, and bay views beyond compare.
The evening tour differs from daytime visits in several ways. The evening ferry ride to Alcatraz circles the island with live narration about Alcatraz’s history. Upon arrival on the dock, visitors receive a guided tour from the dock to the cellhouse level and also have the opportunity to participate in a number of other special tours, activities, and cell door demonstrations offered throughout the evening.
Don't believe what you learned from "The Rock" — Alcatraz doesn't have any underground tunnels. (You can still pick up a DVD of The Rock from the gift shop, though!)
"The audio tour on Alcatraz is excellent, guiding you around the prison at your own pace, with lots of great information, including interviews with former guards and prisoners!"
Visiting Alcatraz is partially a self guided experience which you can do at your own pace. Park Service staff offer numerous free programs throughout the day on a variety of topics: escapes, military history, American Indian occupation, natural history, etc.
Once on the island you can stay as long or as short as you wish - there is a ferry departing about every half hour and you can return to San Francisco on any ferry. We generally recommend at least 2 to 3 hours to fully visit the island.
There are numerous videos and exhibits on the island, as well as the cellhouse audio tour which is included in the price of the ferry ticket.