SE | Lovön: National Defence Radio Establishment

https://www.openstreetbrowser.org/#map=13/59.3332/17.9085&categories=military
59.331800, 17.856406

Wikipedia EN: https://en.wikipedia.org/wiki/National_Defence_Radio_Establishment
DE: https://de.wikipedia.org/wiki/F%C3%B6rsvarets_radioanstalt

Note:
Integrated in Five Eyes coooperation