ALCATRAZ ISLAND — Cold rain falls and clouds obscure the San Francisco waterfront. Light fades from thin slots where prisoners once clamored for a glimpse of the outside world.

On a night like this, three men fled the now-shuttered federal prison that inmates called Hellcatraz. None was ever found, and all were presumed to have died in the cold, shark-infested waters of San Francisco Bay.

About 1 million people tour Alcatraz each year, making it one of the Bay Area's top tourist attractions. While most visit during the day, a night tour provides a more atmospheric glimpse of life on "the Rock." Hands grip cold steel bars and footsteps echo in long-abandoned hallways.

"It makes you really wonder what life was like for people here," said Steve Chamberland, 43, a visitor from Orlando, Fla., who took the evening tour of Alcatraz recently with his wife and two sons.

Never a welcoming place, the prison is even more foreboding after the sun sets. Perched on a rocky islet just north of the San Francisco waterfront, it housed some of the nation's most dangerous criminals, including Chicago mobster Al Capone.

"At first you think it's a tourist spot," Chamberland said. "But then I started thinking that I'm standing where some of the most violent criminals ever lived."

Night tours cost more than day trips, and the proceeds support preservation and restoration efforts.

"We thought it might be more atmospheric," said Sheila Thomas, 42, of Columbia, Md., who booked her night tour in advance on the Internet.

The night begins on Pier 41 at Fisherman's Wharf with an often-chilly ferry ride to the island. As the boat approaches, visitors get a look at what's left of the prison post office and power plant. Some buildings are beginning to crumble, giving the island a ghostly feel.

Alcatraz was first used as a fort in the 19th century, and more than 100 cannons were on hand during the Civil War in case of a Confederate attack. The maximum-security federal prison opened in 1934.

Night visitors hike up a steep path to the main building. They are herded single file through a small door, much like inmates arriving here for the first time.

The audio tour includes recordings of former inmates and guards. Most of the 1,545 men incarcerated here weren't as notorious as Capone, and visitors get a sense of the isolation they knew by looking into their spartan cells and hearing their stories.

One lonely prisoner talks of how he was sustained by the sight of a woman making her way into the prison, while another describes the raucous sounds of New Year's Eve celebrations drifting across the bay on the wind.

The tour takes visitors through the main cellblock, where a barbershop and library once stood. The cells, with Army-style bunks and small toilets, are stifling. And the isolation chambers, where inmates were locked behind two doors and deprived of sunlight, are frightening.

"I couldn't live in one of those little cells," said visitor Susan Fissel, 54, touring during a break from a business conference.

A menu from March 21, 1963 — the last day the prison was open — is still propped up in the kitchen. Inmates had dry cereal, steamed whole wheat and a scrambled egg that morning.

The kitchen was considered the most dangerous place in the prison because inmates were armed with a knife and a fork.

The tour ends with a story of the famous June 11, 1962, escape, apparently executed with a stolen spoon. The story was made into the film "Escape from Alcatraz," starring Clint Eastwood and filmed on location.

Alcatraz was eventually closed by then-Attorney General Robert Kennedy because of decrepit conditions and because it was expensive to maintain.