Ultimate Fighting Championship (UFC) is a U.S.-based mixed martial arts (MMA) organization, currently recognized as the largest MMA promotion in the world. The UFC is headquartered in Las Vegas, Nevada. The UFC was started as a tournament to find the world's best fighters irrespective of their style, and was based upon Brazilian vale tudo fighting. Although there was a limited number of rules, the UFC was initially known as no holds barred fighting and contests were often violent and brutal.