For the last couple of years I have been studying nubs and other features of monolithic structures that were built of stone all around the world, long, long ago. This is very exciting and a little scary in that no one knows how or why the ancient builders built these gigantic, often very ornate structures, with no wheel and no metal, with only the brute force of man and beast to cut, drag, and place the huge, hard stones, fitting them tightly together without mortar. For the first seventy years of my life I gave no thought to how the pyramids and such might have been built, then I made a New Year's Resolution to study the world. I thought that I would be studying geology, instead I found thousands of miraculous stone structures built into the geology of the earth. I study this every day. Google Earth has shown us the world. Wow!
The internet, in particular YouTube, gives free access to videos of monolithic sites in Peru, Egypt, India, Cambodia, Japan, South America, and the Middle East. There is even some documentation on monolithic sites in South Africa, China, North America, and Europe from Scotland to Spain. For example, Turkey is covered with stone circles and menhirs like the one in Kerloas, France. Fascinating!
The Kerloas menhir is a free-standing stone of 100 to 150 tons, cut, transported, and erected in Kerloas, France. Its dimensions are:
Altitude : 132 m.
Current height of the menhir: 9.50 m above ground
Maximum width: 2.20 m
Average thickness: 1.35 m
Its surface is finely-hammered overall, and its summit is beveled. It is porphyroid granite which is 6-7 Mohs on a hardness scale of 10. The Kerloas menhir has two nubs located about one meter above the ground. There are nubs on monolithic structures throughout the world, and no one know why.
Kerloas menhir in France-internet sourced for fair use
Kerloas menhir nub-squared-internet sourced for fair use
Kerloas menhir nub-rounded-internet sourced for fair use