The land includes:
•The earth's surface
•Everything under it (all the way to the center of the earth)
•Everything on it (everything that is appurtenant)
•Everything above it within limitations (all the way to the sky)
Court rulings have pretty much allowed planes and other aircraft to pass over a person's land without permission so "All the way to the sky" must be taken with a grain of salt.
Page url: http://www.georgiaappraiser.com/glossary/index.html?land.htm