This ornate Neo-Byzantine church is situated at the highest natural point in Marseille, a 162 m (532 ft) limestone outcrop on the south side of the Old Port. Adjoining the church of Notre-Dame-de-la-Garde, who is supposed to protect sailors, Espérandieu built a watchtower surmounted by a monumental statue in an almost military style, which harmonizes with the remains of a 16th century fort that serves it as a base. The square bell-tower of 41m (135 feet) is surmounted by a belfry of 12.5m (42 feet) which itself supports a monumental, 11.2m (27 feet) tall statue of the Madonna and Child by Eugène Lequesne made out of copper gilded with gold leaf. The crossing of the basilica is crowned by an elegant Romano-Byzantine dome with refined polychrome geometrical decoration outside and mosaics inside completed by Henri-Antoine Révoil (1820-1900), who succeeded Espérandieu as architect to Marseille Cathedral.