Numbers 80 to 85 in Ancient Astronomy
The site to which you are referring is Sarmisegetusa in old Dacia, which was a well known royal citadel of the Illyrians in Roman times.

Sarmisegetusa was a fortress, not an observatory. The reconstructed posts there were used to hold up ceilings and walls.

Sarmisegetusa backs up against face of the mountain, so half of the horizon cannot even be seen from the site. That fact alone excludes the possibility that anyone was doing any astronomy there.