The Wombat File Is Yours to Keep

We're home this morning with Imogen, hoping to get this quiz out to you while her attention is engrossed by two pegs, an eyedropper, and a plastic pig (some of you may recall the NBC sitcom based on precisely this premise). So pardon us if we get right to today's trivial point:

Of Chile's 5 UNESCO World Heritage Sites, one received its designation because it preserves artifacts more than a millenium in age. Of the others, one is marked for special treatment because -- in the process of dealing with one of the largest natural sources of a particular substance in the world -- it became the center for a vibrant workers' culture. The substance those workers dealt with is famous for its use both in war and peace. What are the artifacts in the first case, and the substance in the second?

First correct answers posted to comments wins five minutes with the pegs and the eyedropper. The pig has already rolled way back under the sofa: can you reach back there and see if you can get it? Oh, no, that looks like a bit of old bagel. No Googling or grabbing your sister's hair. I said no. One guess (at both parts) per comment but comment as often as you'd like.