These are visibly ERECTED, not only modelled. See the photos.

Hi,
I made this one according to "Odins Zeigefinger" which is close (3 km WNW) and has the same significance and it is also in the brochure.
It is truly not natural=stone, it is constructed and partly machined by the people to show equinoxes and solstices. See the photo in the brochure or i can send you mine.
Megaliths definitely aren't always parts of structures. If it is in OSM definition of megalith, it is a mistake.

https://en.m.wikipedia.org/wiki/Megalith
Here you have definition :)

Hi!
I marked this as megalithic because it sits into megalith definition. Its significance can be compared to Stonehenge in England - this is what you can read in the brochure on the web.
The position is even better than on the website, measured by me with accurate GPS.
Have a nice day!