Whenever you spot someone on the Moscow metro taking a photo with their mobile phone, chances are you have just witnessed a combination of two things that are widely popular in the Russian capital.
Transporting an unparalleled 9 million weekday commuters on its 12 lines, Moscow's metro boasts a number of stations that wouldn't look out of place as side wings of the Palace of Versailles.
While Instagram doesn't publish official user figures per country, the sheer volume of photos with Russian-language captions suggests a significant number of the service's 300 million users is Russian.
In fact, the country's most high-ranking user may be Prime Minister Dmitry Medvedev himself.
Combining Russians' love for mobile photography and their pride in the metro system, the Moscow Times has put together a map that shows each station as documented by commuters on Instagram.
Hover over one of the station names on the map below with your cursor to get a glimpse of each station's design. Explore how the architecture changes from classical to more modern as you move from the capital's center to its outskirts.
And if you have some Moscow photos of your own to share, make sure to tag us — you can find the Moscow Times' Instagram account here.
More photos of the Moscow metro: