Castellammare di Stabia, with volcano Vesuvius

Castellammare di Stabia in the Bay of Naples is the modern town that lies where the ancient Roman city of Stabiae was. The eruption of Mount Vesuvius in AD 79 completely buried that town along with a large area of the Bay to north and south. A part of the Roman world that had long been a popular playground for some of the most powerful and wealthy citizens of Rome, ceased to exist. Archaeological excavations have uncovered many expensive villas and palaces as well as large parts of the towns Pompeii and Herculaneum.
The volcano has continued to be a threat to the surrounding area. Its most recent destructive eruption took place in 1944 causing local devastation but nowhere near the scale of what happened in AD 79.