[3] Initially called the Metropolitana Collinare ("Hills metro") it ran for 4 km (2.5 mi) between Colli Aminei and Vanvitelli.

[4] Two years later, in 1995, the line was extended to reach Piscinola[4] giving an overall track length of 8 kilometres (5.0 mi).

In 1997, the city government drew up a new Piano Comunale dei Trasporti di Napoli (City Transport Plan) which called for a review of the network, improved controls over maintenance expenditure and general finances, a new tariff control system and better management of the urban rail network of Naples.

[5] In conjunction with the regional government of Campania, the comune government of Naples incorporated a new fully state-controlled joint-stock corporation called Metronapoli, which was 99% controlled by the comune and 1% controlled by ANM (Azienda Napoletana Mobilità), with a mission statement of: "providing an efficient public rail transport service of quality to the city".

Intended to connect the National Archaeological Museum via the Museo di Capodimonte, providing an alternative route to part of Line 1, the project was abandoned.

The regional government announced a rivoluzione del ferro (rail revolution) which involved a planned expansion of the region's network at a cost of €3.8 billion, and would see the construction of 1,400 km (870 mi) of new tracks and 80 new stations for a total of 423 stations on the network within Campania.

On 3 December 2005, the CIPE (Interdepartmental Committee for Economic Planning) announced over €600 million worth of funding to be spent the Metropolitana di Napoli network.

[7] From 23 December 2006 to 20 February 2007, a special exhibition of models and multimedia presentations was held at Castel dell'Ovo to showcase all of the planned improvements to the Metropolitana di Napoli network, and was extremely well received by locals.

In August 2021, Duomo Station began operating, its steel and glass dome delayed by subterranean archeological discoveries and related funding and construction pressures.

Ente Autonomo Volturno is currently responsible for the transport services and maintenance of Line 11 and pedestrian subways.

[26][27] The goal pursued by the authorities is to build stations that are both functional and simultaneously serve as beautiful and comfortable community hubs; concurrently, there is an aim to urbanistically revitalize the surrounding areas.

These artifacts, dating back to prehistoric, Greek, Roman, Byzantine, Medieval, and Aragonese periods, provide excellent testimony to ancient Naples.

The six stations where the most artifacts were uncovered, located on the lower section of Lines 1 and 6, are: Salvator Rosa, Toledo, Municipio Porto, Università, Duomo and Chiaia.