Which towers do you know are/were used for very special purposes?

I know this:

- BREN-Tower ( http://en.wikipedia.org/wiki/BREN-Tower ) for experiments with unshielded reactor

http://upload.wikimedia.org/wikipedia/commons/5/54/BREN_Tower_nevada.jpg

- Drop Tower Bremen ( http://en.wikipedia.org/wiki/Fallturm_Bremen ) for short 0G-experiments

http://upload.wikimedia.org/wikipedia/en/1/18/Bremen_fallturm.jpg

- Pylon Test Facility Mannheim ( http://en.wikipedia.org/wiki/Pylon_test_facility_Mannheim ) for testing pylons

http://upload.wikimedia.org/wikipedia/commons/e/e2/Mannheim-tower-test.jpg

How knows more tall constructions for very special use?

Something like a huge verticle warehouse? Telecommunications storage and telecommunications exchange facility skyscraper, right in the middle of the city. :cool: