Alcatraz Penitentiary sits atop a small island in the middle of San Francisco Bay, and when the fog rolls in, the bone-chilling dampness permeates every corner. In countless trips there, I have met with the darker sides of human nature, walking in the footsteps of former convicts and guards in places that were never meant to be seen by the public. As you step into a cell, you can sense the emotions trapped in this fortress that inmates called "Hellcatraz."

This legendary American prison is full of peeling paint, rust, crumbling concrete, broken glass - and tremendous sense of scale, with long rows of tiny cells and very high ceilings. The vast, cold silence of its cellblocks, corridors and empty spaces speak volumes for the boredom, hopelessness and routine that made up a day in the life here. It was hard on inmates and guards alike.  

This project has developed over the years into a survey of both its accessible and unknown parts - the off-limits areas that visitors rarely get to see, and it includes three of Alcatraz's recent histories - as military garrison, federal penitentiary, occupied island.