The Moscow metro is one of the most extensive and heavily traveled subway systems in the world, transporting about 9 million people around the city each day.
But it also serves as a sort of museum of Russian history. Opened in 1935, the marble walls, high ceilings, stained glass, mosaics and chandeliers were a testament to the values of Joseph Stalin and his Communist party. Ironically enough, while the stations were built and designed with Soviet labor, the main engineering work was done by British workers.
Stalin ordered the arrest of many British engineers on the project for espionage, because they had gained so much inside knowledge about the city's subway system. The engineers were eventually deported and whatever business climate existed between the two countries was effectively killed.
The system is currently under expansion, and is expected to grow an additional 90 miles by 2020. That would make it the third largest subway system in the world, behind Beijing and Shanghai.
Below, via Reuters, a look into the average day on Moscow's subway system: