The world’s smallest country just half a mile wide with its own £20m train line

At only half a mile wide and with an area of 121 acres (49 hectares), one would assume that the world's smallest sovereign state by both area and population would have little need for a railway. However, that is not the case.

The Vatican City, a city-state surrounded by Rome, has actually had a railway since 1934. Adding to the long list of the state's world records, it is also the shortest railway system in the world. The Vatican Railway opened to serve Vatican City's only station, Stazione Vaticana. The Vatican Railway's main rail tracks are standard gauge, which is used by about 55% of lines worldwide. It is just 980ft (300m) long. Access to the Italian rail network is over a viaduct to Roma San Pietro railway station. The station is near the Vatican Gardens, behind St. Peter's Basilica.

The construction of a railway in the Papal States was prevented by Pope Gregory XVI (1831-46), who is reported to have said "chemin de fer, chemin d'enfer" ("road of iron, road of hell"). His successor, Pope Pius IX (1846-78), began construction of a rail line from Bologna to Ancona.

However, the territory was seized by the armies of the Kingdom of Sardinia in 1860 before it was completed. The pontiff also had plans for a papal train, but this was also never constructed.

The need for rail travel by the mass of pilgrims in the 19th century is said to have helped soften opposition to a railway in the Vatican. Finally, the construction of a railway station and its linkage to Italian rail lines were guaranteed by the Lateran Treaty in February 1929, which recognised Vatican City as an independent state under the sovereignty of the Holy See.

The total cost of construction was reported to be €24 million (£30 million) and the station, built 66ft from the Entrance Gateway and designed by Giuseppe Momo, was constructed between 1929 and 1933.

The first locomotive entered Vatican City in March 1932. Pope John XXIII (1958-63) became the first pope to use the railway during his pilgrimage to Loreto and Assisi. Pope John Paul II (1978-2005) also used the railway a few times for symbolic purposes.

Pope Francis's desire to open the Church's treasures to the public resulted in a weekly special train from Vatican City Station, which is open to the public and provided by the Vatican Museums and the Italian railway. This train tour opened to tourists for the first time in 2015.

Most other rail traffic consists of inbound freight goods, although the railway has occasionally carried other passengers, usually for ceremonial reasons.