Azov, the town from which the sea gets its name, is situated on the river Don about 20 miles from its mouth. It was founded by the Genoese in the 12th century on the supposed site of the Greek colony of Tanais. It has only belonged to Russia since 1774. Once a place of considerable trade, it has sunk into insignificance chiefly because of the silting up of the harbour. The fortifications destroyed by the allies during the Crimean war have only been partially restored.