Barcelona is a city in northeastern Spain and the capital of the Catalonia region. It is the second most populous city in Spain. Its origins date back to Roman times, and today is it a leading center for tourism, economics, and culture. It is noted for the works of Antoni Gaudí, particularly la Sagrada Familia, the unfinished church, as well as many UNESCO World Heritage Sites. The city boasts many museums including The National Museum of Art of Catalonia, the Barcelona Museum of Contemporary Art, and the Picasso Museum.