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 in, around and above a 1.5-million-US-gallon (5,700 m) pool of water, featuring water acts such as synchronized swimming as well as aerial and ground acts. The O theatre, which is designed to look similar to 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.
Starting in late October 2010, Cirque du Soleil starting offering 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