- Official name: Alcatraz Island
- Location/ area: Located 1.25 miles offshore from San Francisco, California, in the middle of San Francisco Bay.
- Size: Approximately 22 acres
- Altitude, terrain type, climate: Elevation ranges from sea level to 135 feet. The island has steep terrain, exposed rock, and coastal vegetation with a cool, foggy maritime climate.
- Major areas/sections: Main Cellhouse, Lighthouse, New Industries Building, Guardhouse, Dock Area, Gardens, and historic ruins from the military and prison eras.
- Age: Established as a U.S. military fort in the 1850s
- No. of visitors per year: Over 1.5 million
- UNESCO World Heritage Site: Listed on the National Register of Historic Places since 1976
- Access: Only by ferry