Rostov-na-Donu, also Rostov-on-Don, or Rostov, city, southwestern European Russia, capital of Rostov Oblast. Situated on a high bank of the Don River near its mouth on the Sea of Azov, the city is an important commercial, industrial, and transportation center. It is connected by a deepwater canal to the Sea of Azov, and by the Volga-Don Canal to the Caspian, Baltic, and White seas. The city is also linked by pipeline with the petroleum fields of the Caucasus region. Manufactures include ships, chemicals, agricultural machinery, electric equipment, and building materials. Several institutions of higher learning, including a university, are in Rostov-na-Donu. In 1749 a customs office was established on the site of present-day Rostov-na-Donu. A fortress was built here in 1761, and in 1797 the settlement achieved city status. In the 19th century it grew as an important trading port. During World War II the city was held twice (1941, 1942-1943) by German forces and was damaged considerably. Population (1999 estimate) 1,005,800.