Riga is the capital and largest city of Latvia, a major industrial, commercial, cultural and financial centre of the Baltics, and an important seaport, situated on the mouth of the Daugava. With 706,413 inhabitants (2010) it is the largest city of the Baltic states. Riga's territory covers 18.60 square miles and lies between 1 and 10 metres (3.3 and 33 ft) above sea level, on a flat and sandy plain. Riga's historical centre has been declared a UNESCO World Heritage Site, and the city is particularly notable for its extensive Jugendstil (German Art Nouveau) architecture, which UNESCO considers to be unparalleled anywhere in the world.