I need your help!!!

So, basicaly, when I was a kid, I had this weird book. It had different puzzels in it, like mental games, and when you solved the whole book, there would be an exact place were if you go to and dig a whole, there would be a reward. I'm talking a serius reward like one of those jem figuriens you see in the windows of diamond stores. I dont know the name of the book, and I was wondering if any of you knew what it was. I'm pretty sure there isnt a diamond statue somewere underground, I just want the book. Thanks!!!!! :)