Terni became an important industrial city in the late nineteenth century with waterpower from the River Nera. The Terni arms factory was begun by the government in 1875 and opened in 1880 in an impressive group of classical buildings around avenues and an internal waterpower canal for turbines. It specialised in making rifles. In 1918 it employed over 7,000 workers. The complex of historic buildings is very large and located on the edge of the city centre.
The museum is in one of the historic buildings of the factory. It displays hundreds of hand guns, rifles, swords and other weapons in glass cases. It also shows some field guns and missiles. There are examples of equipment for making and testing arms.