Quartermaster

The Quarto principal was a large warehouse on Alcatraz Island with substantial storage rooms and loading areas for military supplies. The industrial structure was designed to provision hundreds of people on the isolated island.

The building was constructed during Alcatraz's military phase and continued serving as a storage facility when the island became a federal prison. It survived both major phases of the island's history.

The building shows how supplies were managed to support the island's isolated community. It reflects the practical demands of sustaining a fortress and later a prison cut off from the mainland.

The building is reached by ferry from Pier 33 in San Francisco with advance tickets needed. Doorways are narrow and interior spaces are dimly lit, so allow time to navigate carefully.

The building occupied a central position between prisoner areas and administrative zones, making it essential to daily island operations. Many visitors overlook how critical this structure was to running the entire facility.

Location: San Francisco

GPS coordinates: 37.82806,-122.42410

Latest update: December 15, 2025 13:30