In architecture, a cupola is a small, most-often dome-like structure, on top of a building. Often used to provide a lookout or to admit light and air, it usually crowns a larger roof or dome. The word derives, via Italian, from the lower Latin cupula (classical Latin cupella from the Greek kypellon) small cup (Latin cupa) indicating a vault resembling an upside down cup. Cupolas often appear as small buildings in their own right. They often serve as a belfry, lantern, or belvedere above a main roof. In other cases they may crown a tower, spire, or turret. The chhatri, seen in Indian architecture, fits the definition of a cupola when it is used atop a larger structure.
The cupola is a development of the oculus, an ancient device found in roman architecture, but with the cupola being weatherproof it is superior for the wetter climates of northern Europe, which were influential during the Renaissance.