Alcatraz Island is located in the San Francisco Bay, 1.5 miles (2.4 km) offshore from San Francisco, California, United States. It's infamous for an old penitentiary which is no longer in use.
Scooby-Doo and Scrappy-Doo (first series)
The Richie Rich/Scooby-Doo Show
What's New, Scooby-Doo?
The gang took a tour with Julian Libris as part of their investigation into the San Franpsycho. They were attacked by the monster; it also sailed away in the tour boat, leaving them stranded. This left them highly suspicious of Julian.