Built originally as the Conventual Church of the Knights Hospitaller, the historical associations and its architectural importance make this arguably the most important building in Malta.
The key element of the new capital city the church was constructed between 1573-1577 to the designs of Gerolamo Cassar (1520-1586), chief engineer of the Order. Its exterior is a fine example of muscular, Renaissance design while the interior (ceiling paintings - 1662-67 - by Mattia Preti ) has been called the world's first example of high baroque.
Treasures include: the polychromatic marble floor pavement, Caravaggio's painting, the "Beheading of St. John", and a unique collection of Flemish tapestries. Each side chapel is a jewel.