What is cupulas?

Cupolas (not cupulas) are decorative structures that sit atop a roof or dome. They typically have a circular or polygonal base and a dome-like roof. Cupolas are often used for ventilation or to provide natural light to the space below. They can be made from a variety of materials including wood, metal, and fiberglass. Cupolas are commonly found on churches, barns, and other traditional buildings, but they can also be used on modern structures for their aesthetic value. Some cupolas may also have weathervanes or other decorative elements atop them.