The 26-year-old heiress was booked late Sunday into the Century Regional Detention Facility in Lynwood, an industrial area about five miles southeast of downtown Los Angeles, according to the sheriff's inmate locator Web site.

Paris Hilton (file photo)

Though a judge sentenced her to 45 days behind bars, Hilton is expected to serve only 23 days because of a state law that requires shorter sentences for good behavior, said sheriff's spokesman Steve Whitmore.

Hilton surrendered to sheriff's deputies after making a surprise visit to the MTV Movie Awards in the afternoon.

"I am trying to be strong right now," she told reporters on the red carpet. "I'm ready to face my sentence. Even though this is a really hard time, I have my family, my friends and my fans to support me, and that's really helpful."

"I'm really scared but I'm ready to do this," she added. "And I hope that I'm an example to other young people."

Hilton will be housed in the "special needs" unit of the 13-year-old jail, separate from most of its 2,200 inmates. The unit contains 12 two-person cells reserved for police officers, public officials, celebrities and other high-profile inmates, Whitmore has said. She could have a cellmate.

Like other inmates in the unit, Hilton will take her meals in her cell and will be allowed outside the 12-foot-by-8-foot space for at least an hour each day to shower, watch TV in the day room, participate in outdoor recreation or talk on the telephone. No cell phones or BlackBerrys are permitted in the facility, even for visitors.

A sign near the visitor's entrance reads: "Gang attire (jackets, hats, belt buckles), purses, pens, lighters and umbrellas are not allowed past the lobby. Please leave them, at your own risk, or secure them in a locker or your vehicle."

The jail, a two-story concrete building next to train tracks and beneath a bustling freeway, has been an all-female facility since March 2006.

"I did have a choice to go to a pay jail," Hilton said Sunday, without giving details. "But I declined because I feel like the media portrays me in a way that I'm not and that's why I wanted to go to county, to show that I can do it and I'm going to be treated like everyone else. I'm going to do the time, I'm going to do it the right way."

When she was sentenced May 4, Superior Court Judge Michael T. Sauer ruled that she would not be allowed any work release, furloughs or use of an alternative jail or electronic monitoring in lieu of jail.

Officers arrested Hilton in Hollywood on Sept. 7. In January, she pleaded no contest to the reckless-driving charge and was sentenced to 36 months' probation, alcohol education and $1,500 in fines.

She was pulled over by California Highway Patrol on Jan. 15. Officers informed Hilton she was driving on a suspended license and she signed a document acknowledging she was not to drive. She then was pulled over by sheriff's deputies on Feb. 27, at which time she was charged with violating her probation.