Treninnow Gatepost

Leaning beside a wall just off the military road that runs along the coast at Whitsand bay is this former gatepost. I have to call it that because of the fact that it still has the rusty hinges embedded in it. But it is alone... I could find no other granite gateposts in the area during a two hour walk. The stone is long and slender and stands very near to a field called barrow Field. This is supposed to be the site of the Treninnow Stone Monument (see other posting). Could this stone have been part of the monument?