The Trans-Siberian Railway is a network of railways connecting Moscow to the Russian Far East and the Sea of Japan. Two of its major stops are Omsk and Irkutsk. Omsk is a city in southwestern Siberia, located on the banks of the Irtysh River. It is the administrative center of Omsk Oblast and one of the largest cities in Russia. Irkutsk is a city in eastern Siberia, located on the Angara River. It is the administrative center of Irkutsk Oblast and one of the largest cities in Russia. Both Omsk and Irkutsk are important stops along the Trans-Siberian Railway.