They are pictures of what was probably the largest railway gun graveyard of the war, with four of them there: three K5 (E)s and one K12 (E). As you can see in the first photo, at least some were destroyed to prevent their use, but others look like they might have been in working order in photos. They were all evacuated from the northern French coast in the late summer of 1944 and ended up just outside the village of
Sluiskil, which lies along the canal from Ghent to Terneuzen, because the units were obviously trying to avoid the Allies and blown-up bridges in Belgium. The bridge over the canal at Sluiskil was the only remaining option to withdraw the guns east, but it had been opened and mined by the Germans in defence of what the Canadians would later call the “Breskens Pocket”. As a result of all these guns with their associated railway hardware arriving there, pretty soon none of them could go forward or back and they ended up being abandoned, despite attempts to rescue at least some of them by ship, which were thwarted by German troops working at cross-purposes due to poor coordination between the Army and the Navy.
There are lots of photos on
http://k5e.nl — a lot of generic ones of K5 (E) and K12 (E) guns, but if you go to the “Sluiskil 1944” link at the top of the page, there are tons of photos of these particular ones to be found in the submenus.