15 of the planned 30 stops. A further section of Line C, serving six additional stations, opened on 29 June 2015, as the line's western terminus was moved from Parco di Centocelle to Lodi. On 12 May 2018, the western terminus was moved to San Giovanni (interchange station for line A). After this third phase, the line will be further extended with two stations, Amba Aradam/Ipponio and Fori Imperiali/Colosseo, located in the city centre. A further extension to Piazza Venezia was announced by Mayor Virginia Raggi in July 2019. Progress on the line has been slow with projected completion dates being repeatedly delayed. Rome is one of the oldest cities in the world, and as such, the construction of the Metro system has encountered considerable obstacles owing to frequent archaeological discoveries. While the excavation of the tunnels themselves can be undertaken well below the probable location of most archaeological finds, the excavation of stairwells and ventilation shafts – which must, by necessity, connect with the surface – pose considerable difficulties. The trains operating on line C are completely automated, and use the same AnsaldoBreda Driverless Metro system also featured on the Copenhagen Metro. Archeostation During the excavation for the central route of line C, thanks to the archeological richness of Rome's ground a new type of underground station was born, as in Paris with Louvre–Rivoli station. San Giovanni San Giovanni station was the first archeostation to be opened on 12 May 2018. Excavation to a depth of about 20 metres allowed the exploration of about 21 stratifications of history up to the so-called virgin soil, the one in which man's presence is absent. The exhibition is characterized by being a real tour with libraries for the finds along the route, explanatory panels on the walls and a temporal measurement of the historical phases that follows the path of the passengers from the atrium level to the platforms' level: Atrium level: from Contemporary Age to Late Antiquity Age First underground level: from Republican Age to Archaic Age Platform level: Prehistoric Age The various archaeological finds and exhibits include small items such as gold jewelry, coins, crockery, shells, large amphorae and elements of ancient columns and also large finds, such as the large pool, the largest reservoir ever found, located inside a farm of the imperial age. Timeline Network map Service Fares An urban single journey ticket, the Biglietto Integrato a Tempo