There was probably a day or two worth of exploration in this area, but I had an early afternoon appointment in Maubeuge with M. Jacques Rivant, President of the AMIFORT S.F. Maubeuge. Thus I headed along the Belgian border to my rendevous by the P.O. des Sarts.
I met M. Rivant and 2 of his companions. They took me to the P.O. De Bersilles. There are 4 ouvrages to the north and east of the town of Maubuege. From W to E, P.O. des Sarts, P.O. de Bersillies, P.O. de Salmagne, and the P.O. de Boussois. There are also a number of CORF casemates in the intervals. All 4 of these ouvrage were built on top of Sere de Rivieres forts - you can still see the ditch and counterscarp.
These ouvrages were heavily attacked in May 1940. After their capture, the Germans did further damage to the cupolas and turrets. Very little metal remains.

The entrance to Bersillies was blocked and there was probably not much to see anyway. One thing I found interesting was the exit of the escape hatch from bloc 2.