Was this structure really unique?

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Until 2010, an electricity pylon near Brühl in Germany was equipped with an observation deck. Was this structure, from which you can find a picture on https://de.wikipedia.org/wiki/Anlage...btreusee_I.JPG and which has an entry in our database at http://skyscraperpage.com/cities/?buildingID=120476 really unique as I suppose or do or did also other electricity pylons with observation decks exist?
If yes, where?