The Kaiser Wilhelm Geschutz, commonly known as the Paris Gun, was a long-range 210mm-caliber gun manufactured by Friedrich Krupp AG and operated by the German Imperial Navy. Hidden in the forest of Coucy near Crépy, Aisne, it was used for the first time in World War I on March 21, 1918, to bombard Paris, about 75 miles away. The Paris Gun had a 36m-long barrel with rifled bore, which wore away rapidly and had to be sent back to the factory to be re-bored after 65 rounds had been shot and start using bigger caliber shells (238mm) from then on. Hence, the operation of the Kaiser Wilhelm Geschutz was very expensive. Operated by a crew of 80 sailors, it was mounted on rails, capable of firing 95-kg shells at a rate of four per hour, to a maximum range of 80 miles (130 km), reaching the stratosphere at an altitude of 25 miles to drop down anywhere in Paris.
In August 1918, as the Allied forces moved eastward, regaining lost territory, the Paris Gun was taken back to Germany and was never captured by the Allies. Although the gun was not a practical weapon in terms of military results, it was used to have a psychological effect and destroy the morale of the French people.
Paris Gun (Geschutz) (Video)