Harr my memory. (For details)
In short, in one of the reports proposed in this subject,
You can see a "primitive" people who had received a short visit, Americans or others, but came by plane.
Results of the races, these good people had built an airfield, and made an airplane with branches, in the hope of seeing these visitors from the sky again. It was very impressive.
The problem is that they were filmed, so there was the presence of a cameraman .... how came?
In short, this little story serves to explain why there are many old sites that look like landing strips ...