cupolas

A cupola is a small, often dome-like or polygonal structure on top of a building, serving as a decorative crown, a source of natural light, and a ventilation opening. The term derives from Italian cupola, meaning "little dome," itself from cupula in Latin.

Cupolas sit on a drum or base and may be open to the interior or glazed; they can function as lanterns when they admit daylight through windows or panels. They are built in wood, masonry, or metal, and are frequently clad in copper, tin, or zinc to resist weather and develop a patina. They may be solid or hollow, and some include a railing or pergola.

Purposes include providing daylight to interior spaces, promoting ventilation, offering a lookout or visual focal point, and housing mechanical equipment or bells or clocks. In religious and civic architecture, cupolas often mark important spaces inside or above central domes and can enhance acoustic or scenic effect.

Historically, cupolas appear in classical and Renaissance architecture and were widely used in Baroque and neoclassical buildings. In more recent periods they appear on churches, government buildings, and agricultural structures such as barns for ventilation and light. In modern architecture, cupolas may be purely decorative or incorporated as glass lanterns on contemporary roofs.