The Champ-de-Mars served again as the main site of the Paris Universal Exposition of 1878. A gigantic palace of glass and iron 725 meters long occupied he center of the park, surrounded by gardens designed by Alphand. For the Paris Universal Exposition of 1889, celebrating the centenary of the French Revolution, Alphand placed the Eiffel Tower in the center, near the monumental Gallery of Machines. The Exposition included a Palace of Fine Arts and a Palace of Liberal Arts. The space around the Eiffel tower and between the galleries and palaces was filled by a large landscape garden, which extended along the axis between the Eiffel Tower and the Seine, and ended at the river at a colossal fountain with a group of allegorical figures, called "The City of Paris Illuminates the World with her Torch". The fountain was lit at night by electric lights shining up from the water through plates of colored glass.