The Ultimate Fighting Championship (UFC) features MMA (mixed martial arts) athletes. Unlike professional wrestling, the UFC is closely tied with athletic roots as opposed to theater or performance. Styles of fighting used in the UFC include jiu-jitsu, wrestling, Sambo, judo, boxing, and Muay Thai. The first official UFC event took place in 1993 in Denver, Colorado. The original intention of the UFC was to define which fighting style was the best in the world and their first pay-per-view fight was called War of the Worlds (WOW). Celebrity UFC athletes include Ken Shamrock, Cung Le, Ronda Rousey, Anderson Silva, and Georges St.-Pierre.