On Retronaut, Viktor Bulla's "Pioneers defense drill, Leningrad." It dates from 1937, four years before the Siege of Leningrad, and that makes the weirdness vivid and poignant. So many of the children here would have died in the Siege, or lived through it in the civil defense force, eating wallpaper paste and digging trenches. How brave and ready they must have felt in 1937, though.

Pioneers defense drill, Leningrad