From WIKIPEDIA: The city of Pompeii was an ancient Roman town-city near modern Naples. Pompeii along with Herculaneum and many villas in the surrounding area, were mostly destroyed and buried under 4 to 6 m of ash and pumice in the eruption of Mount Vesuvius in 79 AD.
Researchers believe that the town was founded in the seventh or sixth century BC and was captured by the Romans in 80 BC. By the time of its destruction, 160 years later, its population was probably approximately 20,000, with a complex water system, an amphitheatre, gymnasium and a port. The eruption was cataclysmic for the town. Evidence for the destruction originally came from a surviving letter by Pliny the Younger, who saw the eruption from a distance and described the death of his uncle Pliny the Elder, an admiral of the Roman fleet, who tried to rescue citizens. The site was lost for about 1500 years until its initial rediscovery in 1599 and broader rediscovery almost 150 years later by Spanish engineer Rocque Joaquin de Alcubierre in 1748.