For the 1900 World Fair, it was decided to build the Grand and Petit Palais on either side of a road that would extend across the Seine to the Invalides. Work on the Alexandre-III bridge began in 1897 and was completed a few months before the opening of the Fair. The statues at the top of the pylons are gilded with gold leaf like elements of some of the sculptures on the bridge. The pylons emphasise the axis of the structure, which is directed towards the flamboyant dome of the Invalides. This perspective caused the engineers a great deal of concern, as the single arch also had to be high enough to allow barges to pass through.