O is a water-themed stage production by Cirque du Soleil, a Canadian circus and entertainment company. The show has been in permanent residence at the Bellagio in Las Vegas, Nevada, United States, since October 1998. O, whose name is pronounced the same way as eau, the French word for "water", takes place around and above a pool of water. It features water acts such as synchronized swimming as well as aerial and ground acts. The O theatre, which is designed to resemble a 14th-century European opera house, has 1,800 seats, thus allowing the performance to be watched by 3,600 people a night since the performance usually plays twice in a given day, also designed to meet the special demands of the show. O was inspired by the "infinity and elegance of water's pure form," which pays tribute to the beauty of the theatre. A group of 150 stage technicians assist in the production of the show, the cast of which is 85 performers: international acrobats, synchronized swimmers, and divers. Some of them are former Olympic athletes. History Since late October 2010, Cirque du Soleil has offered backstage tours of the O theatre. The experience allows visitors to see the backstage wings, training rooms, costume workshop, break area, underwater lighting area, and go up to a catwalk into the sound and lighting booths. Not every experience will be the same as the tour is conducted around a "regular day", so performers may or may not be training, rehearsing, or even working out. As of early 2011, O has grossed over a billion dollars since the show opened in 1998. O has received many awards, including the following: Entertainment Design Award, best production show, 1998 Las Vegas Review-Journal, best production show, 1999–2006 THEA, live show category, 1999 Prix Italia, creativity in high definition, 2009, for the documentary Flow O had its 10,000th performance on 1 September 2019. Set and technical information The show has a cast of 85 acrobats, synchronized swimmers and divers performing in and above a 1.5 million-gallon pool. When maintenance needs to be performed, the pool is drained in about 12 hours to the Bellagio Lake, causing the lake's water level to rise . The pool is kept at and has an underwater speaker system and regulators that allow performers to breathe underwater. Every member of the cast is scuba-certified. The underwater stage lift was produced by Handling Specialty.