Plovdiv 40,000 objects. The Museum of Natural Science was inaugurated in 1955 in the old edifice of the Plovdiv Municipality built in 1880. It is among the most important museums in the country with rich collections in its Paleontology, Mineralogy, and Botanic sections. There are several rooms for wildlife and it contains Bulgaria's largest freshwater aquarium with 40 fish species. It has a collection of minerals from the Rhodope mountains. The Museum of Aviation was established on 21 September 1991 on the territory of the Krumovo airbase to the southeast of the city. The museum possesses 59 aircraft and indoor and
History of Plovdiv the city in development of modern trade, banking and industry. In 1939 there were 16,000 craftsmen and 17,000 workers in manufacturing factories, mainly for food and tobacco processing. During the Second World War the tobacco industry expanded as well as the export of fruit and vegetables. In 1943 1,500 Jews were saved from deportation in concentration camps by the archbishop of Plovdiv Cyril who later became Bulgarian Patriarch. During the period of communist governance that followed the end of World War II many large factories were built in and nearby Plovdiv, for example a plant for non-ferrous metals, textile works,