The first thing you notice about ancient Pompeii is the buildings are in generally better condition than those of modern Naples. The second, at least for me, is the proximity to Vesuvius. I knew it was close, but visiting in person I feel I could almost throw a rock at the mountain. And Vesuvius isn't a particularly imposing peak. I don't suppose it was even particularly lofty before the historic eruption. The vegetation running up its sides gives it the appearance of pastoral approachability.
The close geography of the key elements makes it easy to picture the events of 79 AD as an observer from what is now Naples--the cloud of choking hot ash first suffocating Pompeii, then collapse of the mountainside and a superheated pyroclastic flow barreling like a freight train towards those in Herculaneum who had lingered to watch the eruption. The Earth often gives early warning, but in truth four million Neapolitans and their neighbors live in sight of a mountain that could release its pressure at any time. And if it happened today, I could be part of the next archeology exhibit. Almost tempting for a geologist.
