Coupole (cupola)

A voûte (vault) having the shape of half a sphere.
A coupole can have a square, circular, elliptical or octagonal ground surface.
The croisée (crosssing) or the chœur (choir) are often covered with a coupole.
A coupole is often supported from trompes (squinches) or pendentifs (pendentives).
This cupola on trompes is located in the Saint-Martin in Chapaize.

Saint-Martin - Chapaize