London has the world's oldest underground rail system; the New York City subway system has the most stations; the Shanghai metro system is the world's longest; and the title of world's busiest is a closely-fought battle between Shanghai, Beijing and Tokyo. But when it comes to the city with the world's most beautiful metro system, there's a clear winner: Moscow.

To step into a Moscow metro station is to step back in time and immerse yourself in a museum rich in architecture and history. Built under Stalin and opened in 1935, the Moscow metro is an extravagant underworld featuring Art Deco styling, baroque plasterwork, marble columns, elaborate chandeliers, stained glass and ceiling mosaics.

Moscow Metro
Komsomolskaya metro stationMaxim Shemetov/Reuters
Moscow Metro
Komsomolskaya metro stationMaxim Shemetov/Reuters
Moscow Metro
Prospekt Mira metro stationSergei Karpukhin/Reuters
Moscow Metro
Lesoparkovaya metro stationMaxim Shemetov/Reuters
Moscow Metro
Sokolniki metro stationMaxim Shemetov/Reuters
Moscow Metro
Ulitsa Skobelevskaya stationMaxim Shemetov/Reuters
Moscow Metro
Novoyasenevskaya metro stationMaxim Shemetov/Reuters
Moscow Metro
Arbatskaya metro stationMaxim Shemetov/Reuters
Moscow Metro
Chistye Prudy metro stationSergei Karpukhin/Reuters
Moscow Metro
Chkalovskaya metro stationSergei Karpukhin/Reuters
Moscow Metro
Tsvetnoy Bulvar metro stationSergei Karpukhin/Reuters
Moscow Metro
Paveletskaya metro stationSergei Karpukhin/Reuters
Moscow Metro
Turgenevskaya metro stationSergei Karpukhin/Reuters
Moscow Metro
Lyublino metro stationSergei Karpukhin/Reuters
Moscow Metro
Novokuznetskaya metro stationSergei Karpukhin/Reuters
Moscow Metro
Dubrovka metro stationSergei Karpukhin/Reuters
Moscow Metro
Borisovo metro stationSergei Karpukhin/Reuters
Moscow Metro
Cherkizovskaya metro stationMaxim Shemetov/Reuters
Moscow Metro
Rimskaya metro stationSergei Karpukhin/Reuters
Moscow Metro
Proletarskaya metro stationSergei Karpukhin/Reuters
Moscow Metro
A sign reading 'Moscow metro system. Shipilovskaya station'Sergei Karpukhin/Reuters
Moscow Metro
Shipilovskaya metro stationSergei Karpukhin/Reuters
Moscow Metro
Barrikadnaya metro stationSergei Karpukhin/Reuters
Moscow Metro
Sukharevskaya metro stationSergei Karpukhin/Reuters
Moscow Metro
Prospekt Mira metro stationSergei Karpukhin/Reuters
Moscow Metro
Borovitskaya metro stationSergei Karpukhin/Reuters
Moscow Metro
Troparyovo metro stationMaxim Shemetov/Reuters
Moscow Metro
Rumyantsevo metro stationMaxim Shemetov/Reuters
Moscow metro
Dubrovka metro stationSergei Karpukhin/Reuters

One of the most beautiful metro stations, Mayakovskaya – opened in 1938 and named after the Soviet writer Vladimir Mayakovsky – is famous for its 34 ceiling mosaics depicting "24 Hours in the Land of the Soviets." During the Second World War, it was used as a command post for Moscow's anti-aircraft regiment.

Moscow Metro
Mayakovskaya metro stationSergei Karpukhin/Reuters
Moscow Metro
Mayakovskaya metro stationSergei Karpukhin/Reuters

In a country with a modern history so laden with violent upheaval, there is a fine line between reconstructing and celebrating the political undertones of the rich architectural heritage. Lenin's face is everywhere; Stalin's was removed in 1956, three years after his death. A ceiling panel in Belorusskaya metro station, which shows three women holding a hammer and sickle wreath, with the letters CCCP, originally depicted the women reaching to touch a bust of Stalin.

Moscow Metro
Belorusskaya metro stationSergei Karpukhin/Reuters
Moscow Metro
Belorusskaya metro stationSergei Karpukhin/Reuters
Moscow metro
People gather in front of artwork depicting Lenin at Novokuznetskaya metro stationSergei Karpukhin/Reuters
Moscow metro
People walk under a mosaic of former Soviet leader Vladimir Lenin at Komsomolskaya metro stationLucy Nicholson/Reuters
Moscow metro
People stand in front of a mosaic depicting former Soviet leader Vladimir Lenin at Biblioteka Imeni Lenina metro stationLucy Nicholson/Reuters

Only recently under President Vladimir Putin have more favourable references to Stalin crept back into the patriotic narrative of the Second World War. A 2009 renovation of Kurskaya station, surprised people with its inclusion of the words of the Soviet anthem as it used to be sung under Stalin: "Stalin reared us — on loyalty to the people. He inspired us to labour and to heroism."

Moscow Metro
Kurskaya metro stationSergei Karpukhin/Reuters
Moscow Metro
Kurskaya metro stationSergei Karpukhin/Reuters
Moscow Metro
Kurskaya metro stationSergei Karpukhin/Reuters

During the Cold War, stations on the Arbatskaya line were dug deep to serve as shelters in the event of nuclear war. Rumour has it that in the 1950s, Stalin ordered a top-secret line dug deeper than the other metro lines, linking the Kremlin to the airport and a series of nuclear bunkers.

The Moscow Metro has 200 stations and 333.3km (207.1 miles) of track, making it the fifth longest subway system in the world. Around 2.5 billion journeys are made on the system every year, making it the busiest underground rail network outside Asia.