"It's an extraordinary story and one which even Parisians knew very little about," said to The Telegraph leading French historian Professor Jean-Claude Delarue. "The plan was kept secret for obvious reasons, but it shows how seriously military planners were already taking the new threat of aerial bombardment."
The second city was built in 1918, as the war was coming to an end and it never got the chance to be tested but this does not take away from the beauty of its design. First of all, it was built on an area around the commuter town of Maisons-Laffitte on the River Seine close to where the real capital actually was situated.
Famous areas of Paris, such as those around the Arc de Triomphe and Opera, and industrial suburbs, such as Saint-Denis and Aubervilliers, were recreated almost to perfection using wooden buildings complete with details that mimicked the dirty glass roofs of factories.
Perhaps the most important part of this project was recreating Paris' lights. It is called the city of lights for a good reason after all.
The man in charge of the process was an electrical engineer called Fernand Jacopozzi and he handled the task magnificently with white, yellow, and red lamps also used to create the impression of machines in operation at night. No word, however, was said on whether the Eiffel Tower, built in 1887, was recreated.
So, what happened to this city after the war came to an end? It was rapidly deconstructed which is a shame; because today, it would have made for a great tourist attraction.