Cul-de-four (semi-cupola ©)

The translation in the title is followed by this sign ©; this means that it has been "invented" by me.

A coupole (cupola) in the shape of a quarter of a sphere.
This type of voûte (vault) is often found in absides (apses) and absidioles (semi-circular chapels).
The picture shows the cul-de-four in the Sacré-Cœur in Paray-le-Monial.

Sacré-Cœur - Paray-le-Monial