By either digging under it or building upon it without permit or right/writ.
If you strike gold or oil you can’t drill or dig it up if you don’t own the mineral rights to land you think you own. Check your title, if you are so lucky enough to have one, you are a TENANT.
Also, if you wish to improve “your” house upon “your” land, you will need a builiding permit.
So you don’t really own anything if you pay for permission to dig or drill or make a treehouse or make a pool or extend a bedroom or patio or….
Furthermore, for any reason the govt can take your land under imminent domain to …build a wall for example. They have to compensate you but that gets tricky.