Odessa or Odesa is the third largest city in Ukraine. The city is a major seaport and transportation hub located on the northwestern shore of the Black Sea. In the 19th century it was the fourth largest city of Imperial Russia, after Moscow, Saint Petersburg and Warsaw. Its historical architecture has a style more Mediterranean than Russian, having been heavily influenced by French and Italian styles. Some buildings are built in a mixture of different styles, including Art Nouveau, Renaissance and Classicist.