How much time should I allot for my visit?

On average, it's recommended that you set aside a minimum of 2.5 hours for your visit to Alcatraz Island. That time includes taking the round-trip ferry, which is about 15 minutes each way, touring the prison, and walking around the island to explore the gardens and displays. Of course, you're welcome to stay as long as you want. Just make sure to check the schedule for the last ferry back to San Francisco.