CSI: CRIME SCENE INVESTIGATION star Marg Helgenberger is fascinated by the diversity of Las Vegas, Nevada, where the show is set, especially the seedier side.

The cast films the show in Los Angeles, but travels to the desert resort town four times a year to film on location.

She explains, "The strangest thing (about Las Vegas) is always the mix of people, the high-end and the low-end, the down-and-dirty (mixed) with the classy.

"We get to see a lot of the city that most tourists never get to see, sort of the grungier areas.

"One of the places we shot at most recently was an area near the Stratosphere (casino), which is populated by strip clubs and wedding chapels.

"One of the strip clubs actually had a billboard that advertised, 'Home of the Five-Dollar Lap-Dance.' There wasn't a long line!"