A rather amusing 18th Century Hoax that had some rather unfortunate consequences for all parties involved.
Link: Wikipedia on Beringer's Lying Stones
Link: The Geological Society
And you can read (well, I was just there for the illustrations) the original manuscript here: https://books.google.ca/books?id=3PhcAAAAcAAJ&printsec=frontcover&redir_esc=y#v=onepage&q&f=false
Droll indeed, although I can see how wanting so badly to believe led to errors (and mischief) all round...