12. Camouflage Trees for Spies
During World War I, the French Army pioneered the use of camouflage trees—hollow, realistic-looking fake trees placed near front lines to serve as concealed observation posts for Allied spotters. These structures allowed soldiers to monitor enemy movements while remaining hidden, providing a strategic advantage without exposing scouts to direct fire. The British Army adopted this technique, creating their own versions to enhance battlefield intelligence gathering. (Imperial War Museums)
