[Endoperez]

"Imagine trying to live without an available smithy before 1860, or even later in some comunities not readily reached by rail or ship. It simply could notbe done without revenrting to the Stone Age. Certainly, many of our pioneers learned to substitute wood for iron in many instances, but even this would have been virtually impossible without the irreducible minimum of iron and steel tools such as axes and knives and hammers.
The traditional blacksmith's most important function, until mass production replaced him as a tradesman, was supplying the tools of civilization and war. In a large city or a small backwoods settlement he would make, according to his own design or that of his patrons, the hammers, axes, adzes, plane bits, knives, sickles, scythes, auger bits, files, chisels, carving tools, spears, swords, arrowheads, and all other necessities of the various farmers and craftsmen found in a community. All crafstmen were basically dependent on the blacksmith's skill and availability."
The Art of Blacksmithing, by Alex W. Bealer, revised edition

Forges were everywhere. Smelters for making metal weren't quite as common, as most iron and steel could be reworked many times. The aforementioned book describes piles of scrap-metal as a necessary and unavoidable part of any smith's backyard. It also describes simple smelters which could be used virtually everywhere. Making iron didn't become organized industry until the 13th century (when the Catalan furnace was developed), and while this would fit the MA/LA timeframe of Dominions, it wouldn't have the mythical qualities you would give it; that would be simply a way to increase resources, already available to some nations (Ulm) as a resource bonus in forts.


EDIT: it's surprising how little 'lrage' has to do with 'large'.