So I have been playing a lot with the Sweboz (quite fun, and much easier to understand than Greeks, as they don't have the gigantic Helenic trait-line that is also mostly negative), which, of course, means upgrading their capital often. After I settle them, I notice there's a 1k 2 turns building among the options called something along the line of Large Pastoral Region. An upgrade to the (now existing?) Pastoral Region, but offers no apparent bonii, and both on the Strategic section of their description, just state that the region can support a City-cized settlement (which is odd, because I can't seem to have walls bigger than Large Town, which is regular stone walls?). I am a complete noob at the buildings file and my attempts to read it failed. What is this building for?