The city of Naples hides a whole other city under its surface. The visible city is the all-round form of an invisible city that is the inverse mold. This tour aims to retell the relationship between the city of Naples and its subsoil from the foundation up to the present day. The various stages of the tour will show how the inhabitants of the city have always extracted from the underground the "energy" and the materials necessary for life in the upper city and continue to do so. The aspect of Naples and the character of its inhabitants have been shaped by this relationship that looks like it has never been interrupted, but rather to be an integral part of the life that is still taking place here today.

To describe this relationship, this tour takes into consideration the following historical periods of the city: the Greek and then Roman period, the Baroque period, the last 20 years.