Alcatraz Island – San Francisco Bay
In 1909 construction began on the largest reinforced concrete structure in the world – a new military prison necessary because of a large influx of U.S. soldiers convicted of crimes in the Philippines. This building would become the famous U.S. Penitentiary Alcatraz in 1934.
Alcatraz Island – San Francisco Bay
Alcatraz Penitentiary.
Travels With Dan 