If a person owns a piece of land to what depth do they own that land? Is it to the core of the earth? Highly unlikely I know but was just pondering this.
If you buy a plot of land, then what is called "mineral rights" come with it. Therefore if oil, gold or spring water etc is discovered, then the owner takes right.
Not for treasure though.
There is also something about roots extending from other peoples land. But the small print is very boring (no pun intended).
You own the land as deep as you like, (but you can't charge mine workings rent) and you own the air above as high as you like (not that you can do anything with it).
Anything you find on that land is yours except anything generally valuable then the Government will want it.
Gold, oil, etc are examples so if you find any of these, keep quiet !!
Its funny you should say that iggle piggle, I know a farmer (, he was digging a trench and hit something, so he jumped put of the tractor to go and have a look. He found some really old building foundations, like super old. So they dug a few other holes and kept finding them. They filled the holes back in, and pretend it isnt there. The location of the farm would no doubt spark interest as to what the enormous foundations were actually for.