Superstar rapper Lil' Kim (search) donned an orange jumpsuit at a drab and "degrading" federal jail in Philadelphia Monday to begin serving her year-and-a-day criminal sentence for perjury, The Post has learned.

Several sources said Lil' Kim will join a small group of women serving sentences for convictions at Philly's Federal Detention Center (search), where most of the 1,100 inmates are men and women awaiting criminal trials.

Kim, 30, is expected to walk into the jail in the Center City historic district, and surrender at 2 p.m.

After that, she will likely be seen by the jailhouse doctor, strip-searched by guards and made to "squat and cough" to show she has no hidden contraband in her body. She then will be issued an orange jumpsuit.

The rapper — whose real name is Kimberly Jones (search) — was convicted earlier this year of lying to a federal grand jury about a Hot 97 radio-station shootout involving two members of her posse.

Federal prison officials selected the jail for Kim Friday, sources said. Their choice is somewhat of a surprise, considering that many thought Kim would be sent to a low- or minimum-security federal camp.

In fact, sources said officials had considered such a camp in Danbury, Conn., or Alderson, W. Va.

The latter is where domestic diva Martha Stewart served her five-month sentence for lying about a stock sale.

Those camps are set in rural surroundings, with pleasant scenery in the outdoor areas that inmates wander in.

Instead, Kim will do her time in the 11-story, 628-cell jail in Philly that opened in 2000.

"It's one of the most degrading places I've ever been," said Michelle Brix, 29, a Philadelphia woman who served a one-week sentence in the jail in 2004 after being convicted of blocking a federal building during an anti-war protest.

She said everything inside the jail is dull-gray and metal.

Brix said inmates got only one hour of recreation in large cages one hour per weekday and were kept in 80-square-foot cells the remainder of the time. Outdoor light comes into the cells through vertical frosted-glass slits in the walls.

Those surroundings will be a dramatic departure for Lil' Kim, who over the past weekend held court at her fancy, white, two-story mansion in Alpine, N.J.

"I'm not interested in talking, baby," Kim said via her home intercom Saturday.

Later, Kim and several others left in two cars and headed to Club Deep in Manhattan. A production assistant said she was doing an interview for a hip-hop documentary.

Outside the club, a group of hip-hoppers were hanging around.

"Lil' Felon? She's around her somewhere," quipped one.

Yesterday, Lil' Kim's mom and several other friends dropped by her mansion, but the rapper kept out of sight.

Her lawyer, Paul Shechtman, declined comment.

Kim should be settled into jail by the time her new album, "The Naked Truth," hits stores Sept. 27.

She told Newsweek magazine in an interview that she became a "workaholic zombie" after her sentencing in July and rushed to finish the album, which contains songs slamming former members of her posse who testified against her at trial.

"What happened to me wasn't fair," Kim told the magazine. "And lots of people let me down."