Treasure

When I was a child treasure was about as exciting as it got! And these two books sum it all up, the first (masquerade) a children's book with real treasured buried by the author and the second (conundrum) a PR stunt by cadburys both beautifully illustrated and graves the imagination of the British public in the late 70s and early 80s.
http://www.amazon.co.uk/gp/aw/d/0894803697/ref=aw_d_iv_books?is=l

http://www.treasureclub.net/publichunts/conundrum/index.html