Marble and Mondrian: a tour of Moscow's metro

The two newest stations in the Moscow metro - including Rumyantsevo, seen here - are based on the style of the Dutch painter Piet Mondrian. He founded the neo-plasticism movement, reducing his imagery to a series of horizontal and vertical lines. At Rumyantsevo, Mondrian's style was fused with gleaming steel and polished stone. The station is located just short of Moscow's city limits.

Troparyovo station, which opened in 2014, also impresses with its modern style. The large, tree-like installations made of sparkling chrome have featured in many a snapshot. Like other new metro stations in Moscow, Troparyovo is accessible to those of reduced mobility - unfortunately still an exception in the original metro network.

Even during the political turmoil that preceded the collapse of the Soviet Union, the metro continued its expansion - though at the time, stations were usually functional and unadorned. In the 1970s, a simple architectural style was considered modern. Seen here is the Kuznetsky Most station, which opened in 1975.

The most magnificent stations were built under Stalin's rule, ornamented with elaborate stucco, detailed mosaics and lavish paintings. Socialist themes dominated, featuring soldiers, workers and farmers. The artwork in the Kiyevskaya station features pastoral everyday scenes in Ukraine.

Another section of the Kiyevskaya metro station is dedicated to Russia's close relationship with Ukraine. Large mosaics highlight important events and central figures important to both countries. The station opened in the early 1950s - back then, nobody expected that it would ever come to an armed conflict between the allies.

A favorite of many Muscovites is the Novoslobodskaya station. Built in the 1950s, it's smaller and not quite as ostentatious as others from that time. It fascinates passersby with its illuminated stained glass, reminiscent of church windows - actually the original purpose of the colored glass. With indirect light and organic forms, the station gives passengers the impression of being underwater.

Moscow's many metro stations are also impressive aboveground. Known as vestibules, the oft domed structures are most visible in the downtown area - like here at the Park Kultury metro station. Since 1950, it's been a busy transfer point on the Moscow ring line. At rush hour, commuters can expect long lines before even being allowed on the escalators.

The metro isn't just one of the fastest and most reliable transportation options in Moscow - it's also a social meeting place. One often comes across old friends, couples or colleagues, deep in conversation. Mayakovskaya station, which opened in 1938, is one of the oldest in the city. During World War II, it doubled as an air raid shelter.

Ploshchad Revolyutsii station, which opened in 1938, is guarded by lifesize bronze statues of socialist heroes - along with their dogs and chickens. Many passengers reach out and give the rooster's crest or dog's snout a quick rub as they pass by. That's thought to bring good luck.

The glowing red "M" marks the entrance to the Moscow metro, a welcome sight for pedestrians. In massive Moscow, stations often lie kilometers apart. Around 8 million people use the metro every day - more than the populations of Berlin, Munich, Hamburg, and Cologne put together.