Vienna, Austria's capital, is located on the Danube River in the country's east. It is Austria's largest city by area and has a population of about 1.9 million inhabitants. Vienna is well-known for its extensive history and culture, as well as its numerous museums, palaces, and theatres. In addition, the city is home to several world-class universities, including the University of Vienna and the Vienna Technical University. Due to its high quality of life, good public transit, and abundance of natural spaces, Vienna is frequently regarded as one of the most liveable cities in the world. The city is also a major economic and financial center, as well as the headquarters of several international organizations, notably the United Nations Office in Vienna and the Organization of Petroleum Exporting Countries (OPEC).