Thom Hartmann is doing his radio talk show in Peru this week, where he visited the Caral archaeological site over the weekend.
Caral would definitely be on my list of places to visit in Peru. Nearly 5000 years old, Caral is a candidate for a "mother city" where people in the Americas first moved into urban settlement. While there is evidence of trade and religion, there is no evidence of warfare or fortifications at the Caral site.
Caral speaks to the question of how cities and civilization itself evolved. Did people first move into cities to protect themselves and to organize for warfare, or for trade and community? Caral suggests that trade and community came first.
If civilizations are born in peace, and only become warlike later either because of greedy elites or threat of invasion, it opens the door for the possibility of a more peaceful future for global civilization.