An acroterion or acroterium is an architectural ornament placed on a flat base called the acroter or plinth

Plinth

In architecture, a plinth is the base or platform upon which a column, pedestal, statue, monument or structure rests. Gottfried Semper's The Four Elements of Architecture posited that the plinth, the hearth, the roof, and the wall make up all of architectural theory. The plinth usually rests...

, and mounted at the apex of the pediment

Pediment

A pediment is a classical architectural element consisting of the triangular section found above the horizontal structure , typically supported by columns. The gable end of the pediment is surrounded by the cornice moulding...

 of a building in the Classical

Classical architecture

Classical architecture is a mode of architecture employing vocabulary derived in part from the Greek and Roman architecture of classical antiquity, enriched by classicizing architectural practice in Europe since the Renaissance...

 style. It may also be placed at the outer angles of the pediment; such acroteria are referred to as acroteria angularia. The acroterion may take a wide variety of forms, such as a statue, tripod, disc, urn, palmette

Palmette

The palmette is a motif in decorative art which, in its most characteristic expression, resembles the fan-shaped leaves of a palm tree. It has an extremely long history, originating in Ancient Egypt with a subsequent development through the art of most of Eurasia, often in forms that bear...

 or some other sculpted feature.