Prague is the capital and largest city of the Czech Republic. Situated in the north-west of the country on the Vltava river, the city is home to about 1.3 million people, while its metropolitan area is estimated to have a population of over 2.3 million. The city has a temperate oceanic climate with warm summers and chilly winters. Prague has been a political, cultural and economic centre of Europe and particularly central Europe during its 1,100 year existence. For centuries, during the Gothic and Renaissance eras, Prague was the permanent seat of two Holy Roman Emperors and thus was also the capital of the Holy Roman Empire. Later it was an important city in the Habsburg Monarchy and the Austro-Hungarian Empire, and after World War I became the capital of Czechoslovakia. The city played major roles in the Protestant Reformation, the Thirty Years' War, and in 20th-century history, during both World Wars and the post-war Communist era. Prague is home to a number of famous cultural attractions, many of which survived the violence and destruction of twentieth century Europe. Main attractions include the following: Prague Castle, the Charles Bridge, Old Town Square, the Jewish Quarter, the Lennon Wall, and Petan hill. Since 1992, the extensive historic centre of Prague has been included in the UNESCO list of World Heritage Sites.