It's been more than 20 years since Cirque du Soleil premiered "O," but the water-based show continues to dazzle, even as Cirque productions have spread across the Las Vegas Strip.

Before opening "O," Cirque was known for its slightly more traditional circus-arts shows, like its first Vegas production, Mystère (which is also still going, after more than 25 years). For "O," Cirque had the chance to build a custom theater and design the show and the space at the same time, which allowed the company to create a production whose form and function are intricately intertwined.

The set for "O" includes a 1.5 million-gallon pool, with constantly shifting platforms that can provide performers with a solid surface or plunge them deep into the water, depending on the needs of each scene. It makes for a mesmerizing world, both in the graceful way the performers navigate the waters and in the dreamlike nature of the characters and the abstract, impressionistic story.

The ever-changing stage set-up can position performers in various places, providing a panorama of complex acrobatics happening everywhere the audience looks. With new set pieces rotating in on a regular basis, "O" remains as fresh and delightful as when it first opened.

Bellagio, 7 & 9:30 p.m. Sun. & Wed.-Sat., additional 7 & 9:30 p.m. Dec. 23-24, starting at $99 plus tax and fee. 702.693.8866