[vierasmarius]

To bring this back to the OP, the initial question is about a nonmagical TL3 society with very little metal. Is this even feasible? If magic were available, then Essential Stone / Wood might stand in for Iron and Bronze. But lacking that, just how far can technology develop without metal tools?

Of course, the immediate example that springs to mind is the Aztecs and other tribes of pre-colonial South America, who lagged far behind in metallurgy yet still achieved impressive engineering feats. They might be considered to display TLs ranging from 1 to 3, though I suspect much of the claims of how advanced they were are exaggerations based on colonial guilt. Anyways, if there were a TL3 stone-based society I suspect it would look something like that.