Using a hand held GPS, I was able to find each of the points of intersection, and calculate and find the center point of each of the figures. There have been some interesting things there. For example, at the center of another hexagram, I found a museum called Mt. Uniacke house , which is a rather lovely property named after its original grantee. The property has been given to the people of Canada, and his home made into a museum. There are many interesting things about the property and most of them are not advertised in the brochure.
Nobody knows why, but they assume that it represents the triumph of good over evil.
I asked if the curator if she was aware of the significance of the placement of the monument. She was not, nor was she really interested in speculating. I have found several nice explanations for what the symbol means to various groups. If you have any thoughts, please email them to me. A spike with a square iron washer has been driven through the top.