Mannequins at the Hoa Lo Prison Relic displaying leg stocks. Each cell in Hoa Lo had a cement bed and stocks that were used to hold prisoners for months at a time as a means of punishment. The POWs found the stocks to be particularly painful as they were undersized for the average American. Members in solitary confinement at “Alcatraz,” a small prison near Hoa Lo reserved for strong resistors, were locked into the stocks every night, sometimes for years at a time (courtesy of Shawn Vreeland).