On a high school trip, fifty years or so ago, we went through Zacatecas, and I can't remember whether it was day or night. We were dazed from the miles and lack of sleep and sheer overwhelming new information to process. What I do remember is an aqueduct built by the Spaniards in the colonial era to supply water to the mining town of Zacatecas. As an un-traveled kid from Denver, it was the oldest man-made object I had ever seen. Yesterday, while roaming around the old town of the old silver ciy, there it was once again. And while it hadn't changed, my perspective certainly has. I've seen Roman aqueducts and cave paintings from 13,000 years ago. But it was impressive still.