160 acres what would you do :)

Level the entire area.
Save trees, rocks, dirt, etc.
Take the $275000 and hire some laborers to dig out an underground city. You can lay this out with SolidWorks or other CAD program.
Finish underground part. Place dirt back on top.
Use rocks to build a castle using modern tech like solar panels with village in front area and surrounding protective wall. If you hire cheap labor from local home depot type stores they can finish castle and you'll probably have some cash left over. Take the wood from trees and build village. Rent out shops and housing to local peasants.

You could also Level the land and grow pot for a hefty profit depending on local law etc.