sirmiah

And by great hall I mean great mill.

So, I can't seem to figure out building prerequisites. In my last game, I had the technology to build the great hall, but it wasn't an option. I know for a fact no other civ had it yet. I also couldn't build a brewery or a harbor, despite having the techs for those, too. Is there some documentation anywhere about prerequisites for these buildings? The manual has absolutely nothing, and a quick look over the forums doesn't reveal anything, either.<