Ryazan is the largest city and administrative center of Ryazan Oblast, Russia. The city is located on the banks of the Oka River in Central Russia, 196 km southeast of Moscow. As of the 2010 Census, Ryazan had a population of 524,927, making it the 33rd most populated city in Russia, and the fourth most populated in Central Russia after Moscow, Voronezh, and Yaroslavl.