The Universal Exposition of 1889 took place from 6 May until 31 October 1889 and celebrated the centenary of the beginning of the French Revolution; one of the structures on the grounds was a replica of the Bastille. It took place on the Champ de Mars, the hill of Chaillot, and along the Seine at the Quai d'Orsay. The most memorable feature was the Eiffel Tower, 300 meters tall when it opened (now 324 with the addition of broadcast antennas), which served as the gateway to the exposition. The Eiffel Tower remained the world's tallest structure until 1930. It was not popular with everyone; its modern style was denounced in a public letter by many of France's most prominent cultural figures, including Guy de Maupassant, Charles Gounod and Charles Garnier. The largest building was the iron-framed Gallery of Machines, at the time the largest covered interior space in the world. Other popular exhibits included the first musical fountain, lit with colored electric lights that changed in time to music. Buffalo Bill and sharpshooter Annie Oakley drew large crowds to their Wild West Show at the exposition. The exposition welcomed 23 million visitors.