Rich:

Thanks for the "old-timer" map...nothing noted to identify the site.
I have cropped and marked the location as the lat-long indicates.

From yours… Source: Wikipedia Commons - Public Domain)


Also...I have created a drawing indicating the relative size as close as can be determined from the Google readings.


Indications are that its location may be relevant to other sites on the plateau of similar mystique.

Best.
Clive