<P> Nowadays the square is officially named Place du Trocadéro et (and) du 11 Novembre (for the WWI armistice), although it is usually simply called the Place du Trocadéro . </P> <P> The hill of Chaillot was first arranged for the 1867 World's Fair . For the 1878 World's Fair, the (old) Palais du Trocadéro (1878 - 1936) was built here (where meetings of international organizations could be held during the fair). The palace's form was that of a large concert hall with two wings and two towers; its style was a mixture of exotic and historical references, generally called "Moorish" but with some Byzantine elements . The architect was Gabriel Davioud . </P> <P> The concert hall contained a large organ built by Aristide Cavaillé - Coll; the first large organ to be installed in a concert hall in France (it has since been modified twice, and eventually moved in 1977 to the Auditorium Maurice Ravel in Lyon, where it is still in use today). The organ was inaugurated during the 1878 World Fair with a concert in which Charles Marie Widor played the premiere of his Symphony for Organ No. 6 . The building proved unpopular, but the cost expended in its construction delayed its replacement for nearly fifty years . </P> <P> Below the building in the space left by former underground quarries, a large aquarium was built to contain fish of French rivers . It was renovated in 1937 but closed again for renovation from 1985 until May 22, 2006 . The space between the palais and the Seine is set with gardens, designed by Jean - Charles Alphand, and an array of fountains . </P>

Who created the tower that lies across the seine from the palais de chaillot