survey

[Carl1408]

Some 16 years i sold 1ace out of 5 ace of land i owe. I fence off this 1 ace. this land has been sold to a third person. they have been there eight to nine. The survey that was done when third person bout the 1 ace was shown the survey tape is steal on the post where pin is. We now found this survey pin is in the wrong place. The fence is13 feet over on the one ace. My question is the fence that was there for 16 years ans except as corner of the property line. and i have taken care of this land. Is this land mine now.