Stone 16 is finely worked on the north eastern side, where it is on the side of the midwinter sunset alignment. The surface has been finely pecked to a smooth and straight surface, except for a nobble. This protrusion appears to have had its outer most part broken off but appears to have been deliberately left. It is just below head height.
I have no explanation for it and I try to avoid Pareidolia but it is reminiscent of a breast, or is that just me?
Click to embiggen
UPDATE - I learn that "The giant 9.5m menhir of Kerloas in Plouarzel was deliberately smoothed but two projecting bosses were left on either side. These were later associated with fertility, marriage and healing properties if you rubbed yourself against them" Frenchpostcardsofmegaliths @PhilWat09037421