If you found a one-of-a-kind prototype of a revolutionary new mobile phone lying on a public bench, what would you do with it? Does the value of a parcel of land come only from the profits it can gen

If you found a one-of-a-kind prototype of a revolutionary new mobile phone lying on a public bench, what would you do with it? 

Does the value of a parcel of land come only from the profits it can generate? If not, what makes land valuable? Does it ever have any value that is not recognized by the law?

What is the role of governments in regulating the use of any form of property?