This imposing edifice was built on Longchamp plateau to commemorate the arrival of the Durance canal water in Marseille. The first stone of this monumental water tower was laid by the Duke of Orleans in 1839. Espérandieu's second great project in Marseille, the Palais Longchamp, was one of the most accomplished and theatrical buildings of its period. The perspective along the Boulevard Longchamp emphasizes the central Château d'Eau, the outflow of the Canal de Marseille, which is a domed triumphal arch, from which the water flows, flanked by open quadrant colonnades. Below them the fluid forms of the staircases and fountain basins are flanked by the museums of fine arts and natural history, which enclose a space devoted to the celebration of water. Espérandieu's sculpted and painted decorations are a triumph; the benefits and prosperity brought by the waters of the Canal de Marseille are evoked by images that rejuvenated the iconography of the fountain as a monument.