Monte Carlo, Monaco

Monaco-Monte-Carlo is the only railway station in the Principality of Monaco. Interestingly, the station and the entire railway are located underground. So is it a train station or a metro station? Interesting question indeed. In the 1990s, the station and the entire railway were completely re-routed underground closer to the city center. The construction began in 1993 and in 6 years the station opened its doors on 7 December 1999. A curved tunnel 22 meters (72 feet) wide, 466 meters (1528 feet) in length and 13 meters (42 feet) in height has 3 tracks accessed from a side and an island platform.