Dorm like rooms, shared bathrooms, 6:45 a.m. wakeup calls: it's not boot camp, it's rehab at Promises Treatment Center, where celebrities including Charlie Sheen, Lindsay Lohan, Britney Spears and Robert Downey Jr. have come seeking treatment for substance abuse. ABCNews.com recently toured the grounds of Promises' centers in Malibu and Los Angeles, Calif. to get a sense of how celebrities undergo rehab. Pictured here, the main house of the Malibu facility. <a href="http://abcnews.go.com/Entertainment/charlie-sheen-shines-light-promises-rehab-center-stars/story?id=13048850" target="external">Click here to find out what happens when stars go to rehab</a>.

While Promises' program demands hard work, it offers a relaxing atmosphere. Malibu's campus boasts multiple heated pools and hot tubs.

Mountain vistas enhance Malibu's aura. Promises CEO David Sack said that a popular goal of clients is to be able to hike up to the top of the hill pictured here in the background.

Gorgeous places for reflection and discussion abound in Malibu.

Clients are expected to spend time with each other and their therapists in secluded settings like this.

Pathways from the main Malibu facility lead to smaller buildings that house more clients. A total of 36 people can stay at Promises' Malibu center at one time.

Danny Bonaduce, a Promises alum turned detractor, said of the center's Malibu facility, "I remember thinking that if this place had a bar, it would be fantastic."

Most bedrooms at Promises facilities in Malibu and Los Angeles are shared.

With good behavior and progress, clients can "graduate" to single, more picturesque bedrooms.

Clients in Malibu can also pay extra to secure a single room.

Stars, they're just like the rest of us: tabloids and board games are used to pass the time in Malibu.

For more than 10 years, clients at Promises Malibu have painted tiles and added them to an ever-growing mosaic.

Funny, whimsical, spirtual: the tiles run the gamut. One reads "Don't relapse or you'll have to come back."

Promises' Los Angeles campus is achored by two buildings. One, pictured here, is a house that was brought to L.A. from Pasadena, Calif. and reconstructed on-site.

L.A.'s second building, like the first, is a non-descript structure on a residential road.

Bedrooms in Promises L.A. are smaller than those in Malibu. Jason Levine, executive director of the L.A. center, said that while the people who go to Malibu "tend to be masters of the universe or well known people or people who have money -- here, you tend to get the children of those people or the middle class types."

As in Malibu, in L.A., taking well to Promises can get a client promoted to a better bedroom. Unlike Malibu, L.A. offers no single rooms.

No spa cuisine here: home cooking is always on the menu at both facilities. Pot roast and gumbo are two favorites.

Pictured here, the mandatory schedule for Promises L.A. clients on February 21, 2011. There's not a lot of downtime.