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 Airport and a tie-up between Hainan and Plovdiv Airport Invest. On 28 March 2018, Bulgarian Government awarded the consortium of HNA Group and Plovdiv Airport Invest a 35-year-long concession on Plovdiv airport in return for investments reaching €79 million, including a new cargo and passenger terminal. On 19 of July the consortium of HNA Group and Plovdiv Airport Invest have declared that it won't sign the concession contract which opens the road for the classified on the second place to take the concession. On the west side of the airport is located 24th Helicopter Air Base of the Bulgarian Air Force,