The historic center of Naples tumbles so effortlessly downhill toward the sea that you might not know the seafront area actually has a different name all its own—Mergellina.
Mergellina actually used to be a separate town, but when Naples grew it was eventually subsumed by the expanding metropolis in the early 20th century. Today, this neighborhood sits between the foot of the Posillipo Hill and the Bay of Naples. There are many restaurants and hotels in the area, and it's ideal for an evening stroll in the summer.
If you're taking a ferry from Naples out to Sorrento, the Amalfi Coast or any of the islands, it's likely that your departure dock will be in Mergellina. It's not the main port for the big cruise ships, but it's where many of the small hydrofoils and other smaller boats depart.