Fascinating isn't it!I didn't know there was so many around the world.
I love Archaeology. I truly believe we mingled a lot earlier than science can currently provide due to the degrading of materials such as wood.
After all the Stone Age should have been called the Wood Age. Stone Henge is older than the Pyramids, and all the Cairns around maybe as a collective they swapped from Round Cairns to Rectangular structures still following the same stone mound building techniques.