Re: Life After Humans (buried artifacts)

I've noticed a lot of posts inspired by "Life After People".  May I
recommend the inspiration for "LAP", "The World Without Us"?  It's a
book by Alan Weisman, and if I remember correctly, it goes into more
detail about underground structures (like the caves of Cappadocia) and
the soil signatures of human activity left behind (though I think it
focuses more on lead and cadmium than, say, gold).