If you had a 2,400 square foot building, one level with no interior walls and it was located in a rural area, how would you use it to make money?

Assume power was to the building and water was very close by and could easily be brought to the building.

Here's the non-hypothetical part: I have just such a building on my property. It's an old potato cellar and is dug into the earth about four feet. A truck can drive into it, though, as it has a large doorway and a hill leading to it. I had considered converting it to a greenhouse but am reconsidering that idea right now as I'm not sure it's the right idea. I'm convinced there is a way to use this building to my financial advantage but I just need to discover what that is.

Any ideas?