The nature of these structures has been much disputed.
And all three structures may be converted one into the other (Schimper).
Here structures have been observed which resemble nuclei in some of their characteristics.
Do not anchor to any manmade structures including the penstock system large metal pipe.
He grabbed an order of French fries and a burger at the drive-in of a national chain, eating on the road, licking the salt from his fingers as he searched among the glass and steel structures for the address he had jotted down earlier.