This is the All Seeing Eye. It is on the Great Seal of the United States of America and it is on the dollar bill. It represents God watching over mankind. It is also known as the Eye of Providence. The Great Seal was also a symbol that belonged to Freemasonry.
This is one of the most beautiful gates I have seen leading into a cemetery. I realize there are other mysteries on this gate, telling you in a secret code something about John White and his family. One even suggests a hidden treasure, though I believe it is of a Godly nature. If cemeteries like this fascinate you, as they do me, then stopping to see this one should be on your list!