Optina Pustyn monastery is located near a little town of Kozelsk in Kaluga Region (250 km to the South-West from Moscow). Kozelsk became famous in XIII century, when it managed to defend for 7 weeks against Mongol hordes. If you dare ask why Mongols spent so much time in such an insignificant place, I can tell you a slightly different story. These "hordes" consisted of not more then 3 tumens (tumen = 10000 warriors). And Kozelsk citizens killed Mongol negotiators, which was one of the severest crimes according to Mongol law ... (more)