Sicily: Mount Etna
Everybody knows Pompeii story – an ancient Roman city buried in 20 feet/6 meters of ash in 79 AD when Vesuvius erupted. Ash and pumice preserved the city and the artifacts for years. You can now roam the vast squares, streets, several amphitheaters, houses, baths, and so on. The stone streets are particularly awesome with grooves for chariots and large stones for pedestrians to cross the streets which also doubled as sewage. And almost every street you look up and see the Vesuvius towering right above you.