So, i found a cave entrance....

[LimaZulu]

I you don't see any gray wall tiles, that means there's no ore, correct?

[DestructoMonkey]

I just realized something.

If you can't build within 2 squares of a wall... how the hell do you do something like wall off a section of cave? Or is that impossible?

[Zamte]

That rule only applies to actual cave, with the light gray flooring. Once you've found a bit of metal and opened up a large area by mining it out, you can build whatever you want inside of it, even right up against unmined space. I'm not sure if you're able to pave/build over cave floor if you mine out it's walls, or if it still ties it to walls which used to be there being too close though. Either way it won't be possible to wall in everything, but you can wall off the sections you've mined out yourself at least.