I'm not sure who first coined Stonehenge of the North for Thornborough, It might have been me! but I don't think so.

I know that as early as 1908 they were being compared to Stonehenge - "Thornbrough Rings are collectively a monument as impressive as Stonehenge itself" A. Hadrian - Earthworks of England

They have also been called The Avebury of the North and the Flag Fen of the North (my usage). but these have been dropped as a way of conveying the importance of the site to the outside world as nobody knows what they are.

My latest exagerated superlative is "Westminster Abbey of the Neolithic Age" but even I can't compare with Mark Hortons "single largest earth moving operation in early prehistory" which was interpreted by our local press as a "Neolithic quarry".