 A well-camouflaged German 75-mm (7.5-cm) PaK 40 anti-tank gun with a clear view of a straight road and any enemy armor, that may come down on it; Italy. October, 1944.

Camouflaged anti-tank gun

A German 105-mm light field howitzer leFH 18 at a firing position near the city of Smolensk, in western Russia; July 1941.

Battle of Smolensk

24 cm Theodor Bruno Kanone (E)

From Wikipedia:

The 24 cm Theodor Bruno Kanone (E - Eisenbahnlafette (railroad mounting)) was a German railroad gun used during World War II in the Battle of France and on coast-defense duties in Occupied France for the rest of the war. Six were built during the Thirties using fifty-year-old ex-naval guns. --Corrected...