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
Plovdiv It attracts more than 600,000 visitors from many countries. The city has had a duty-free zone since 1987. It has a customs terminal handling cargo from trucks and trains. Plovdiv's geographical position makes it an international transport hub. Three of the ten Pan-European corridors run into or near the city: Corridor IV (Dresden–Bucharest–Sofia-Plovdiv- Istanbul), Corridor VIII (Durrës-Sofia-Plovdiv-Varna/Burgas), and Corridor X (Salzburg–Belgrade-Plovdiv-Istanbul). A major tourist centre, Plovdiv lies at the foot of the Rhodope Mountains, and most people wishing to explore the mountains choose it as their trip's starting point. The city is a major road and railway hub in southern