Syani is one of the largest man made underground systems in Moscow Oblast as well as all of Russia.
Location: village Starosyanovo Map
Found: no later than 14th century
Total length: over 19 km long
Temperature: 7-10 ° C
Syani name is roughly translated as "take off" or "cut off" as a reference to the white stone that was extracted from here. Syani was used as a quarry of white stone that was used by Grand Duke Dmitri Donskoi in his construction of a first stone Kremlin in the late 14th century. In fact it gave a nickname for Russian capital "white- stoned" (белокаменная). Some of the remains of the white Kremlin can still be seen in some of the corners of the medieval fortifications. In fact the name became so synonymous with Moscow that much later during the reign of Ivan III then the walls were rebuild, red brick was actually painted white every couple of years to make it look white. This practice was carried until the early 20th century.
The quarry in Syani was actively used until late 19th century, but gradually decreased. By the time of the Russian revolution only some local peasants used it for its direct purpose. Then commies came to power these underground passage ways were used for execution of political prisoners. Several rounds and even a revolver from that time period can still be found here. Needless to say a lot of stories surround Syani and many people who visited this place reported seeing ghosts, hearing screams and gunshots in the depths of the tunnels.
Moscow Kremlin at the Time of Grand Duke Dmitri Donskoy (14th century) above and 19th century depiction below