A comprehensive summary (in English) including drawings of the orientation of the circle can be found here:
heritageaction.wordpress.com/2011/01/27/the-mysterious-moroccan-megalithic-menhirs-of-mzora/
Professional treatise (in French) can be found here:
journals.openedition.org/encyclopedieberbere/589
Moreover, English baronet Sir Arthur de Capell Brook mentions the place twice in his book Sketches in Spain and Morocco (published in 1831).
This page describes an "ancient pillar" of unknown origin in the mountains about three days' journey from Tanger:
babel.hathitrust.org/cgi/pt?id=mdp.39015073766282&seq=339&q1=ancient
and here is a description of what the place looked like back then:
babel.hathitrust.org/cgi/pt?id=mdp.39015073766274&seq=53
Something is not right. This message is just to keep things from messing up down the road