Budapest is the capital and the most populous city of Hungary, and one of the largest cities in the European Union. It is the country's principal political, cultural, commercial, industrial, and transport centre, sometimes described as the primate city of Hungary. According to the census results of 2011, the population of Budapest is 1,733,685, down from its 1989 peak of 2,146,639. The Budapest metropolitan area is home to 3,271,110 people, about one-third of the country's population.
The city has around 80 geothermal springs, the largest thermal water system in Europe. Its rich history dates back to the Roman Empire, when it was known as Aquincum, and then the capital of the Hungarians in the Middle Ages. It was an important city in the Austro-Hungarian Empire and it played a key role in the Hungarian Revolution of 1848. Today, Budapest is a member of the European Union and it is home to many cultural and architectural landmarks, including Andrássy Avenue, the Chain Bridge, the Buda Castle, the Fishermen's Bastion, the Gellért Hill, the Széchenyi Chain Bridge, the