Sadly, this building and adjacent parts were once Belgrade's main train station, where I arrived on my first trip here from Paris in 1976. Memories abound of that trip, later trips in and out of country, picking up/seeing off friends...
Belgrade's much criticized new project, Belgrade Waterfront, a series of deluxe apartments, walkways, etc. is growing, and spaces is needed. Apparently this building will remain and some say will be a museum. All the tracks are gone.... The new station is a pitiful one, not even so close to the city center.
Progress....or rather, money-grabbing.