We are on a headland on the south side of the "Rock" - the Alcatraz penitentiary where for three decades the most dangerous inmates in America were incarcerated, until Bobby Kennedy, as Attorney-General, ordered it closed in 1963. Behind us stands the concrete and glass model laundry block where Al Capone used to toil for a wage of 7 cents an hour. The concrete is blistered now, its steel reinforcing rods exposed and warped by the salt air.
Its ramparts and grey cliffs as forbidding as its history, the island lies in the middle of the estuary that feeds out beneath Golden Gate to the Pacific. In all, 36 inmates attempted to escape this place. Although five bodies have never been accounted for, it is thought none made it out alive.
Inside the prison building itself, an audio-tape tour helps conjure up its ghosts, with narrations by former inmates and guards. It takes you through the cell-blocks and beneath the "gun galleries" where the screws would pace with rifles ready to shoot to kill in case of trouble.
Today there is a special visitor. He is Glenn Williams, who spent six years here as a convict in the mid-Fifties after a spectacular career as a bank robber. Eighty years old now, he is here to sign copies of his autobiography about his experiences as an Alcatraz alumnus. He politely dedicates the volumes and poses for photographs with the tourists. He particularly enjoys rubbishing the various Hollywood renderings of what happened on the island, including the most famous of them all, the 1972 Escape from Alcatraz, starring Clint Eastwood.
But when asked whether Alcatraz's unholy reputation was deserved, Mr Williams' cheer vanishes. It was so inhuman, he explains, that the inmates would discourage even their families from visiting.
So what, I ask Mr Williams, does he make of the current rush by American politicians to wind back the clock in the prison system by doing away with privileges like televisions and games rooms and even, in several states, reintroducing leg-irons and chain gangs? In this state, where prisons are the second-largest industry, there have even been murmurs about reopening Alcatraz. Some who visit the island today may be viewing it with nostalgia for how incarceration used to be, rather than with regret, as is surely intended.
Jackie Gilbertson of Scottsdale, Arizona, voices just such an opinion even as she presses forward to get Mr Williams's autograph.
"If they can refurbish the island, they could use it again," she ventures. "I think that would be good. I think things have gone too far towards rehabilitation, because crime is still rising".
Mr Williams responds tersely: "They will never open Alcatraz again. It would serve no purpose." He served on a chain gang in Georgia during the Forties, and deplores their reintroduction.
When Kennedy shuttered this benighted place, he declared: "Let us reject the spirit of retribution and attempt, coolly, to balance the needs of deterrent and detention with the possibilities of rehabilitation."
But in the America of Newt Gingrich and the Republican Right his wordsare no longer in political vogue.