Starting with a fake Paris built to lure Kaiser Bill's incendiary bombs, through to the pretend industrial towns used in WWII England to divert 900 tonnes of munitions, to the pretend airbases built in the Pacific Northwest and through to the Viet Cong's pretend villages to disguise tunnel complexes.
The fake Paris never worked, but the English efforts in the next war are remembered as being very effective. D-Day troops were accompanied by dummy paratroopers and inflatable tanks to draw enemy fire.. Today, North Korea's Kijong-dong is a fake town intended to fool distant viewers into thinking that the country's cities are thriving, bustling, prosperous places.
Although only a small fraction of the fake city was ever completed, it had running trains, as well as replicas of the Arc de Triomphe and the Champs-Élysées. It had working lights (just dim enough to convince the Germans that the French had closed their curtains to disguise the city), and industrial sectors, with a translucent paint applied to the roofs to mimic dirty glass ceilings. The partly-built city was never attacked, and quickly disassembled at the end of the war. The Germans were, apparently, developing similar plans for their industrial bases, but the war ended before those plans could be put into action.
In the Second World War, German bombing raids on England intensified. Almost nightly, the Luftwaffe's bombers droned above London, and although the anti-aircraft weapons were much more powerful than during the First World War, so too were the aircraft. The Battle of Britain raged in the skies, with more than 90,000 civilian casualties. The British authorities needed to not only protect their military assets, but also to protect the people from German bombings. They borrowed the plans of the French, whether deliberately or through convergent evolution.
Around the United Kingdom, various potential targets were identified, focused primarily on military hardware, with false tanks, aircraft, and factories constructed to fool German bombing raids. After the bombing of Coventry, however, they expanded this project with the construction of Q-sites.
And who can forget the brilliant ruse that won the day in the historical documentary Blazing Saddles?
Counterfeit Paris & Other Fake Cities Built in the Name of Espionage [Chris White/Atlas Obsura]