Last month (April 2016) I saw this 2A6 Shilka on display where I also saw this Buk 9A310.
The Shilka is a self-propelled, radar guided anti-aircraft weapon system (SPAAG) shooting down aircraft with quad AA rapid fire guns. Also used against infantry, land vehicles and even armored machinery.
I think it's the first time I saw one up this close.