This Italian commemorative stamp, issued in 1967, honors Baroque architect Francesco Borromini (1599–1667). It features a striking view of his masterpiece, the church of San Carlo alle Quattro Fontane in Rome, celebrated for its dynamic façade and intricate dome. The stamp, denominated L.90, was released by Poste Italiane to mark the 300th anniversary of Borromini’s death. It beautifully captures the architectural genius that helped define Rome’s Baroque skyline. The stamp is postmarked and bears the inscription "I.A.S. ROMA 1967" at the bottom.