Rostov-na-Donu (Rus. rəstôf´-nə-dənōō´) or Rostov on the Don (rŏ´stŏv, Rus. rəstôf´), city (1989 pop. 1,019,000), capital of Rostov region and the administrative center of the Southern federal district, SE European Russia, on the Don River near its entrance into the Sea of Azov. It is a major port and rail hub and an important industrial, cultural, and scientific center. One of Russia's leading producers of agricultural machinery, Rostov-na-Donu also has ship and locomotive repair yards, plants processing food and tobacco, mechanical engineering works, and factories that manufacture chemicals, building materials, electrical equipment, road-making machinery, furniture, clothing, footwear, and leather goods. A customshouse was built on the site in 1749, but the city grew around a fortress erected in 1761 and named for St. Dmitri of Rostov. Chartered in 1797, it was named Rostov-na-Donu to distinguish it from the older city of Rostov. It grew rapidly after the opening of its port in 1834 and was a major grain-exporting center throughout the 19th cent. Its position as a center for trade between European Russia and the Caucasus area also gave it the name "Gateway to the Caucasus." The city suffered much damage in World War II and had to be rebuilt after the war.