This is an apolitical forum for discussions on the Axis nations and related topics hosted by the Axis History Factbook in cooperation with Christian Ankerstjerne’s Panzerworld and Christoph Awender's WW2 day by day.
Founded in 1999.
Thank you very much for your quick answer, Jopaerya.
In the book "Atlantikwall" of Alain Chazette (pag.339) there are a very similar image of this gun, identified , indeed, as a 16.4 cm K.M. 93-96 (f) gun of Fort de Locqueltas (Bttr.2/MAA 264)
I agree with Roland1369 , a 138 mm Mle 1910 of the French coast batterie Requin .
After 1940 the batterie was called M.K.B. La Coubre Ost ( Gironde ) by the Germans.
It's hard to see but the gun with the combination with the typical filling of cammonet ,
then my best option would be the 15 cm S.K.C/28 in V.P.L. at M.K.B. Coubre-West ( Gironde ).