The ruins of Pompeii are located near the modern suburban town of Pompei (nowadays written with one 'i'). It stands on a spur formed by a lava flow to the north of the mouth of the Sarno River (known in ancient times as the Sarnus).
Pompeii, Italy. Pompeii - Forum and Vesuvius. Brooklyn Museum Archives, Goodyear Archival Collection
Today it is some distance inland, but in ancient times it would have been nearer to the coast. Pompeii is about 8 km (5.0 mi) away from Mount Vesuvius. It covered a total of 64 to 67 hectares (170 acres) and was home to approximately 11,000 to 11,500 people on the basis of household counts.[4] It was a major city in the region of Campania.