The three signs or symbols I have seen at KGC sites are:
1. Symbol for Goddess Athenia or Menerva. Being in the form of the letter "B" in cursive writing and looking like "13" also a for the letter "M" again Mernerva.
2. A triangle usually a right triangle with the numbers 3,5,7 in one form shape or another.
3. A snake well carved pointing the way with directions. Patches with directions also. or a pumpkin face.
Here's another picture that shows a final layout shaped like a right triangle. This carving shows the last 3 symbols in the layout which has a perimeter of 1000 feet.