Madrid is of course the capital of Spain. It is also Spain's largest city, lying on the river Manzanares in the centre of the country. Whilst it has many modern developments, it has managed to preserve the look and feel of many of its historic neighbourhoods and streets. Landmarks include the Royal Palace of Madrid; the Teatro Real with its restored 1850 Opera House; the Buen Retiro Park (1631); the imposing 19th-century National Library building (1712); an archaeological museum; three superb art museums, viz the Prado Museum, which hosts one of the finest art collections in the world, the Museo Nacional Centro de Arte Reina Sofía, a museum of modern art, and the Thyssen-Bornemisza Museum, housed in the renovated Villahermosa Palace.The population of the city in 2005 was roughly 3.2 million.