The Gulf of Naples, also called the Bay of Naples, is a roughly 15-kilometer-wide (9.3 mi) gulf located along the south-western coast of Italy. It opens to the west into the Mediterranean Sea. It is bordered on the north by the cities of Naples and Pozzuoli, on the east by Mount Vesuvius, and on the south by the Sorrento Peninsula and the main town of the peninsula, Sorrento. The Peninsula separates the Gulf of Naples from the Gulf of Salerno, which includes the Amalfi Coast.

Mount Vesuvius is a somma-stratovolcano located on the Gulf of Naples in Campania, Italy, about 9 km (5.6 mi) east of Naples and a short distance from the shore. It is one of several volcanoes forming the Campanian volcanic arc. Vesuvius consists of a large cone partially encircled by the steep rim of a summit caldera, resulting from the collapse of an earlier, much higher structure.