My brother, Keith, and his family lived in Naples for a few years and I had the opportunity to visit them a little over a year ago.  Naples actually spreads up the slopes of Vesuvius, which is crazy because an eruption of Pompeii proportions (or worse) is nearly inevitable, according to this article.  Visiting Pompeii was one of the highlites of the trip, but it provides a frightening look at what an eruption can do, and sadly, probably will do again.