Question: What was the venue where UFC 191 was held originally called?

full_context: Document 1: Las Vegas Festival Grounds: Las Vegas Festival Grounds (formerly MGM Resorts Festival Grounds) is a 33 acre open-air venue located on the Las Vegas Strip, north of the MGM-owned Circus Circus Hotel and Casino in Winchester, Nevada.
Document 2: MGM Grand Garden Arena: The MGM Grand Garden Arena (originally known as the MGM Grand Garden Special Events Center) is a multi-purpose arena located within the MGM Grand Las Vegas on the Las Vegas Strip.
Document 3: UFC Fight Night: dos Anjos vs. Alvarez: UFC Fight Night: Dos Anjos vs. Alvarez (also known as UFC Fight Night 90) was a mixed martial arts event held on July 7, 2016 at the MGM Grand Garden Arena in Las Vegas, Nevada.
Document 4: UFC 148: UFC 148: Silva vs. Sonnen II was a mixed martial arts event held by the Ultimate Fighting Championship on July 7, 2012 at the MGM Grand Garden Arena in Las Vegas, Nevada. It was the seventeenth UFC event of the year. The card consisted of eleven bouts, with six televised live on pay-per-view, four preliminary bouts on FX, and one on Facebook.
Document 5: MGM Resorts International: MGM Resorts International is a global hospitality and entertainment company operating destination resorts in Las Vegas, Mississippi, New Jersey and Detroit, including Bellagio, MGM Grand, Mandalay Bay and The Mirage. The company recently opened MGM National Harbor in Maryland and is developing MGM Springfield in Massachusetts. It has a majority interest in MGM China Holdings Limited, which owns the MGM Macau resort and casino and is developing a gaming resort in Cotai. MGM Resorts owns 50 percent of CityCenter in Las Vegas, which features ARIA Resort & Casino. It has a majority controlling interest in MGM Growth Properties, a real estate investment trust.
Document 6: T-Mobile Arena: T-Mobile Arena is a multi-use indoor arena on the Las Vegas Strip in Paradise, Nevada. Opened on April 6, 2016, the arena is a joint venture between MGM Resorts International and the Anschutz Entertainment Group.
Document 7: UFC 91: UFC 91: Couture vs. Lesnar was a mixed martial arts event held by the Ultimate Fighting Championship (UFC) on November 15, 2008 at the MGM Grand Garden Arena in Las Vegas, Nevada.
Document 8: MGM Grand Detroit: The MGM Grand Detroit in Detroit, Michigan, is one of three casino resort hotels in the city, and one of four in the Detroit–Windsor area. The luxury resort hotel opened on July 29, 1999, with a grand event which included models and celebrities including Ashanti, Kid Rock, and fireworks. It is the first luxury casino resort hotel in a major metropolis outside of Las Vegas. Detroit is one of the largest American cities and metropolitan regions to offer casino resort hotels.
Document 9: UFC 195: UFC 195: Lawler vs. Condit was a mixed martial arts event held on January 2, 2016, at the MGM Grand Garden Arena in Las Vegas, Nevada.
Document 10: UFC 141: UFC 141: Lesnar vs. Overeem was a mixed martial arts pay-per-view event held by the Ultimate Fighting Championship on Friday December 30, 2011, at the MGM Grand Garden Arena in Las Vegas, Nevada.
Document 11: UFC 191: UFC 191: Johnson vs. Dodson 2 was a mixed martial arts event held on September 5, 2015, at the MGM Grand Garden Arena in Las Vegas, Nevada.
Document 12: Madison Square Garden: Madison Square Garden, often called "MSG" or simply "The Garden", is a multi-purpose indoor arena in the New York City borough of Manhattan. Located in Midtown Manhattan between 7th and 8th Avenues from 31st to 33rd Streets, it is situated atop Pennsylvania Station. It is the fourth venue to bear the name "Madison Square Garden", the first two (1879 and 1890) of which were located on Madison Square, on East 26th Street and Madison Avenue, with the third Madison Square Garden further uptown at Eighth Avenue and 50th Street. The Garden is used for professional basketball and ice hockey, as well as boxing, concerts, ice shows, circuses, professional wrestling and other forms of sports and entertainment. It is close to other midtown Manhattan landmarks, including the Empire State Building, Koreatown, and Macy's at Herald Square. It is home to the New York Rangers of the National Hockey League (NHL), the New York Knicks of the National Basketball Association (NBA), and since 1997, the New York Liberty (WNBA).
Document 13: MGM Grand Las Vegas: The MGM Grand Las Vegas (formerly Marina and MGM-Marina) is a hotel and casino located on the Las Vegas Strip in Paradise, Nevada. The MGM Grand is the largest single hotel in the United States with 5,124 rooms. It is also the third-largest hotel complex in the world by number of rooms and second-largest hotel resort complex in the United States behind the combined The Venetian and The Palazzo. When it opened in 1993, the MGM Grand was the largest hotel complex in the world.
Document 14: UFC 146: UFC 146: dos Santos vs. Mir was a mixed martial arts (MMA) pay-per-view event (PPV) promoted by the Ultimate Fighting Championship (UFC) on May 26, 2012 at the MGM Grand Garden Arena in Las Vegas, Nevada. The main card featured five MMA bouts which were shown on PPV, as well as seven preliminary bouts which were shown on FX, and Facebook. This was the first time in UFC history that the main card featured all heavyweight bouts. It was the twelfth UFC event of 2012.
Document 15: UFC 193: UFC 193: Rousey vs. Holm was a mixed martial arts event held on November 15, 2015, at Etihad Stadium in Melbourne, Australia. It is the most attended UFC event in the history of the company, with 56,214 people filling the stadium. Although Ronda Rousey was heavily favored to defeat Holly Holm, Holm gave Rousey her first career defeat.
ground_truth: MGM Grand Garden Special Events Center