FOLSOM, Calif. - ''STOP: No visitors beyond this point,'' warns the sign overlooking the hand-hewn gray granite walls, vaulted gate and peaked Gothic guard tower of Folsom State Prison.
It's an intimidating view of the lockup where nearly 100 men were hanged and guards and inmates died in spectacular escape attempts that included a runaway railroad engine and homemade diving suit.
Yet the warning sign is posted at a ''picture spot'' where about 9,000 tourists each year snap photos of the prison made famous by country singer Johnny Cash and his ''Folsom Prison Blues.''
Visitors can explore a nearby scale model of the wall, tower and No. 8 gate from California's second-oldest prison. They can view a replica cell featuring mildly risque pinups on the wall and watch a videotaped tour of the prison, which sits on now-valuable acreage in an increasingly affluent community next to popular Folsom Lake.
The Folsom Prison Museum offers a look at torturous prison conditions in the decades after the California Gold Rush populated the Sierra Nevada foothills that start here, 20 miles east of Sacramento.
''It's a novelty, anytime you have a museum about a prison. It opens the door to secrets they had not experienced,'' says John Fratis, treasurer and operations manager of the nonprofit association of retired guards that runs the museum. ''We thought we'd educate the public, because people don't know what it's all about.''
Prison construction began in 1878 on the site of the ramshackle Stony Bar mining camp along the American River. Early guards spent their spare time sifting sand for gold flakes; the land under the prison is said to be veined with gold.
Those were the days when cold stone 4-by-8-foot cells were lighted and heated with candles or oil lamps, and water was hauled in by wagon.
Inmates spent much of their time in the dark behind solid iron cell doors, peering out through 6-inch eye slots. Air holes were drilled in the doors only in the 1940s. The cell doors are still in use.
Tales of those days of hardship are told at the museum by ''Sam,'' a life-size Charles Bronson look-alike talking doll dressed in black-and- white striped inmate clothing.
Other exhibits offer mute but chilling testimony to life at the prison into the early part of the 20th century.
Just inside the door are two thick hemp ropes that actually hanged inmates. Each rope was pre-stretched to minimize the bounce; each rope was used just once, then tagged and stored with the dead man's inmate number. The hangman's knot was custom-tied for each condemned inmate, based on his neck size, with the intention that the large knot would knock him unconscious on impact.
From the first execution on Dec. 13, 1895, to the last Dec. 3, 1937, 93 men hanged at Folsom before California switched to a gas chamber at San Quentin.
A canvas-and-leather straitjacket was deemed so cruel its use was banned in 1912, as was the use of ''The Iron Claw,'' a sinister-looking restraint device. Troublesome inmates were strung up by their thumbs from iron rings set in the walls for that purpose, or hobbled by ankle weights or a ball-and-chain.
A World War I .30-caliber water-cooled machine gun was used until the 1950s to protect the prison armory.
Guards fired a belt of ammunition the first day of each month ''to keep it operational and for the psychological effect,'' according to the museum. It replaced a hand-cranked Gatling gun that was set at the prison boundaries to guard against mass escapes before the high stone walls were completed in the 1920s.
Conditions had improved by the time Cash recorded his ''Folsom Prison Blues'' album at the prison in January 1968. Inmates' shouts, curses and the sound of slamming cell doors accompany an album centered on seven songs about prison life and death.
Cash is traveling overseas and could not be reached to reminisce. In the liner notes to the album, Cash writes that: ''I have been behind bars a few times. Sometimes of my own volition, sometimes involuntarily. Each time, I felt the same feeling of kinship with my fellow prisoners.''
Today, nearly 4,000 inmates can relate to Cash's lament, ''I'm stuck in Folsom Prison - and time keeps draggin' on.''
Folsom, which shifted to housing medium-security inmates eight years ago, started as one of the nation's first maximum security prisons, built to house those serving long terms, the condemned, and the incorrigibles.
Those inmates were desperate to escape.
In 1920, three convicts hijacked a prison train used to move materials, smashing it through a prison gate. Only two were recaptured.
Another inmate tried to escape in 1932 using a diving suit fashioned from a football bladder, goggle lens and other scrounged material.
''He only made one mistake. He didn't make his breathing tube long enough,'' says Floyd Davis, a prison guard for 13 years who now volunteers at the museum.
Guards had to drain the power house mill pond to recover the inmate's body.
Another inmate carved a wooden semiautomatic pistol for a 1937 escape attempt in which Warden Clarence A. Larkin and two others died. Next to the weapon in a prison display case is material inmates used to make bombs.
A wall of the museum is lined with dozens of crude inmate-made knives, known as ''shanks'' or ''shivs,'' including two with blades that fold like pocketknives. Also included are two spears with shafts made of tightly rolled newspapers hardened with a soap-and-water solution.
''I guess when you've got nothing to do all day you can come up with all kinds of neat things,'' says John Spotswood of Folsom, who brought his visiting parents to see the displays.
Nearby is a crude but working toaster made of wires installed inside a cardboard box.
John Moore, who retired 22 years ago as a prison lieutenant and now volunteers at the museum, says inmates used to tear asbestos insulation off steam pipes and use the heat to cook strips of meat. The ends of each steak remained raw, however, because the inmates couldn't hold cook them without getting burned; those portions were fed to the prison's cats.
The prison museum is the only one operating in California - and one of the few in the nation - though San Quentin plans to reopen its museum shortly.
''It's a once-in-a-lifetime opportunity to see the tools of the trade, so to speak,'' says Sharyn Ahlstrom of Folsom. ''I bring all my out-of-town visitors here. They all want to see Folsom Prison. Everytime I go around the country, people ask where I'm from. I say Folsom; they say, 'Oh, you live by the prison?' Johnny Cash made it famous.''
Her brother, Bob Wade of Little Rock, Ark., said he was struck by the model prison cell's stark confines.
''You saw that and think, If that's a consequence of doing wrong, you'd better do right,'' Wade says.
The retired guards opened the museum in the late 1980s and pay rent to the prison.
They make their money - much of which goes to charity - from donations and selling souvenirs such as T-shirts and sweatshirts labeled ''Folsom Bed & Breakfast,'' ''Hard Rock Hotel-Folsom Prison'' and ''BADBOYZ'' on a replica California license plate - a reference to the fact that all state license plates are manufactured inside.
It's up to volunteers such as Moore, who spent nearly 33 years as a guard, to break the news to visitors that while Folsom's best-known publicist served time in jail, he saw the inside of prisons only when performing for inmates.
''Everybody always wants to come see where Johnny Cash did his time,'' Moore says. ''When I tell 'em Johnny Cash never did any time in any state or federal prison, they get mad.''