In architecture, a tympanum (plural, tympana; from Latin and Greek words meaning "drum") is the semi-circular or triangular decorative wall surface over an entrance, door or window, which is bounded by a lintel and an arch. It often contains sculpture or other imagery or ornaments. Most architectural styles include this element.
In ancient Greek, Roman and Christian architecture, tympana of religious buildings usually contain religious imagery.. A tympanum over a doorway is very often the most important, or only, location for monumental sculpture on the outside of a building. In classical architecture, and in classicising styles from the Renaissance onwards, major examples are usually triangular; in Romanesque architecture, tympana have a semi-circular shape, or that of a thinner slice from the top of a circle, and in Gothic architecture they have a more vertical shape, coming to a point at the top. These shapes naturally influence the typical compositions of any sculpture within the tympanum.
In medieval French architecture the tympanum is often supported by a decorated pillar called a trumeau.