>‼ New satellite images show that Russia has been building a large-scale radio reconnaissance facility in the Kaliningrad region for two years, just 25 kilometers from the NATO border, — Bild.

This is a ring antenna array, system of antennas used for military radio reconnaissance and communications.
>The facility’s diameter may reach up to 1,600 meters.

Once completed Russia will be able to intercept NATO radio communications in Eastern Europe and the Baltic states, as well as establish more reliable communication with submarines in the Baltic Sea and the North Atlantic.