A natural formation like a hill or a pond can be real property. So can an artificial addition such as a house, a driveway, or a garden shed. If someone owns the land that any or all of these things are situated on, that person has the right to use, manage, and dispose of it. These rights have come down to us from English common law. They are, of course, constrained by state and local laws. You may own a barn, but if you decide to open it up as a weekend party house, local zoning laws and your neighbors may have some say in the matter.