By People Staff
Updated July 14, 2010 01:00 AM

It’s the end of an era!

After four years and six seasons, MTV’s hit show The Hills bid adieu to Hollywood – with a Hollywood ending that included a surprise twist.

The show’s current star Kristin Cavallari celebrated the series finale at the monumental Roosevelt Hotel with fans and past and present costars, including Lauren Conrad, Audrina Patridge, Brody Jenner, Justin "Bobby" Brescia, Stephanie Pratt and Holly Montag.

Gathered in a private room, where they sipped champagne, munched on hors d’oeuvres and chatted amicably, the show’s stars and crew watched the final scene, in which Kristin says a tearful goodbye to Brody, presumably for good, before it’s revealed that it was all shot on the back lot of a studio, implying that the show is no more real than Hollywood blockbuster. As the camera panned away, the set came down and Kristin jumped out of the car and rushed to hug Brody. A final shot focused on the landmark Hollywood sign.

Cavallari, who recently told PEOPLE, “Nothing you see on TV is real,” says the show’s surprise ending was a dream come true for her and Jenner. “Brody and I were speechless when we filmed the finale,” Kristin told PEOPLE at the party. “We couldn’t have asked for a better ending. Producers probably knew the cast would reveal secrets, and it’s better to be in on the joke than to look like an idiot. I couldn’t be happier.”

So happy, in fact, that as the credits rolled in the VIP viewing area, the cast and crew erupted in cheers and chanted executive producer Adam DiVello‘s name. Toasts by DiVello, Cavallari, co-executive producer Liz Gateley and others followed, with DiVello saying he had “one-thousand times more fun making the show than anyone had watching it,” before adding, “I love you guys!”

But the finale party wasn’t without drama. Montag, whose estranged sister and former Hills star Heidi was noticeably absent from the festivities, broke into tears during the live aftershow, when she told the audience she still hasn’t heard from her sister, but has faith she will at some point.

Following the after show’s filming, the entire cast – Jenner, with his mom in tow, but without his current gal pal Avril Lavigne; Conrad with her parents, but sans beau Kyle Howard; and Kristin, attached at the hip with new man Miguel Medina – gathered by the hotel’s pool, where they hugged, laughed, sipped drinks and posed for photos with fans. –Dahvi Shira

Tell us: What did you think of the final episode of The Hills?