tympanum (tĭmˈpənəm) [key]. In architecture, the triangular space of a pediment, or low-pitched gable, above a portico, door, or window. Its boundaries are generally cornice moldings. The term also designates the solid wall space above an arched window or door. Sculptured tympana of this type, within round or pointed arches, occurred above the doors of the recessed portals in the medieval churches. They were universal in both Romanesque and Gothic periods, and were especially fine in France. The usual subjects are biblical and symbolic, often arranged in horizontal tiers with numerous figures to illustrate a complete legend. Over the central doorway of Notre-Dame de Paris is a depiction of the Last Judgment. In Italy tympana were sometimes decorated with mosaic or fresco.