Alcatraz Penitentiary - SOLD 2.55" Showcase Concrete

This is an authentic piece of concrete from Alcatraz Penitentiary. Yes, an actual piece of “The Rock!"

This particular specimen measures 2.55" along the widest point.

This specimen, from the famous Alcatraz island, saw some 1,500 prisoners pass by it during the prison's operation. A certificate of authenticity is included.