The indestructible diva, who retired from touring in 2005, will star in a song-and-dance spectacle starting May 6 at the 4,100-seat Colosseum in Caesars Palace. She’ll perform four shows weekly for one month, then return mid-August through early October, leapfrogging stints with Bette Midler. Her pact with promoter AEG Live extends three years.

Cher, 61, promises a “visually unbelievable” hit parade that entails elaborate choreography, complex staging, eye-popping costumes, 14 dancers and four aerialists.

“Creatively, we’re doing something that’s never been done with sets,” she says. “Getting the whole thing in book form, in pictures, has taken months. Our set moves down from the ceiling, in from the sides, up from the floor. We have screens in the foreground, the center and the back. We can change a city into a forest in two seconds. You’ll see a different stage for every song.”

The music will access all chapters of Cher’s career, from her Sonny & Cher start to her recent dance-pop phase, and she’s plotting updates of both old and new hits.

Cher’s extravagant 2002-05 Farewell Tour rang up $192.5 million from 273 shows, the ninth-highest-grossing tour in history, according to Billboard Boxscore.

“Cher definitely achieved elite status as a live performer on her Farewell Tour, which was a remarkable endurance test and a hugely popular draw,” says Billboard touring editor Ray Waddell. “With her elaborate costumes, long list of hits and over-the-top presentation, I can’t think of another artist more suited to Vegas. A Cher concert is just a really good time.”

Cher insists her Vegas splash won’t recycle Farewell’s motifs: “I’d like to be challenged.”

She hasn’t seen Colosseum concerts by previous residents Celine Dion or Elton John, nor the venue itself (“I saw a picture of it”). She’s furiously working out to gear up for rehearsals, and she likes the idea of bouncing between her home in Malibu and a steady gig in Vegas.

Show Dates (2009):

Feb.: 21 – 22, 24 – 25, 28

March.: 1, 3 – 4, 7 – 8, 10 – 11, 14 – 15, 17, 20 – 21

April.: 25 – 26, 28 – 29

May: 2 – 3, 5 – 6, 9 – 10, 12 – 13, 16 – 17, 19 – 20, 23 – 24