This very seasonal photo is from the Facebook page of "Association Ligne Maginot Bois de Cattenom"
The Association has a number of works under their care. This is part of the largest work they have, the Gros Ouvrage A15 Galgenberg, an artillery work with six blocks and two entries. I think this is the Munitions Entry Block. A15 is situated to the North East of Thionville, close to the border with Germany.
Their FB page also has an internal photo,
This page scan below is of page 95 from "Hommes et Ouvrages de la Ligne Maginot - Tome 3" by Mary and Hohnadel. At the top left is the entry block as it was in April 1940.