The following outline is provided as an overview of and topical guide to Naples: Naples – capital of the Italian region Campania and the third-largest municipality in Italy. Naples is one of the oldest continuously inhabited cities in the world. Naples has the fourth-largest urban economy in Italy, after Milan, Rome and Turin. It is the world's 103rd-richest city by purchasing power, with an estimated 2011 GDP of US$83.6 billion. The port of Naples is one of the most important in Europe, and has the world's second-highest level of passenger flow, after the port of Hong Kong.