Vergil's tomb bears the inscription:
Mantua me genuit; Calabri rapuere; tenet nunc Parthenope; cecini Pascua, rura, duces.
Why does "Parthenope" refer to Naples?
The name Parthenope originally refers to a Siren who killed herself after failing to attract Odysseus/Ulysses and his men with her songs. She threw herself into the sea and drowned, and her body washed ashore (see The Roman Paratext: Frame, Texts, Readers).
The locals who settled in the area where her body washed ashore, the Cumaeans, decided to name their newly-built city in her honor, calling it Parthenope. This is thought to have happened sometime around the 7th century B.C. (see Remembering Parthenope: The Reception of Classical Naples from Antiquity to the Present). However, some archaeological diggings have suggested that the city was actually built sometime earlier, in the 8th century B.C. That said, evidence suggests that the city was destroyed, perhaps by burning down. The inhabitants named it Neapolis, or "new city".
It's another question entirely as to why Vergil would want to refer to the old city, and not the newer one. He was 700 or so years too young for it. It's possible that he was trying to reference the history of the region, but it still seems rather strange.