Chancel (choir railing ©)

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

A low ballustrade or railing of wood or metal placed between the chœur (choir) and the nef (nave). A small gate gives access to the choir.
The plan comes from Wikipedia; the picture shows the humble chancel with opened gate in the Notre-Dame of Chazelle (Cormatin).

Chancel - Wikipedia

Notre-Dame - Chazelle (Cormatin)