A professional local guide will meet you at the entrance to the museum. Discover the temporary and permanent exhibitions in the museum during your 1.5 hour tour. This spectacular building adds to an area where the Nervión makes its marks with pleasant riverside walks. The Guggenheim Museum Bilbao is surrounded by promenades, parks and recently-built squares, where you can see the work of artists such as Louise Bourgeois, Eduardo Chillida, Yves Klein, Jeff Koons, and Fujiko Nakaya. Since opening in 1997, the Guggenheim Museum Bilbao's acquisitions have focused on works from the mid-twentieth century to the present day, thus complementing the collections of the Solomon R. Guggenheim Foundation and forging a unique identity at the same time. Visited by about one million people every year, one of its main attractions is the ArcelorMittal gallery, which is a large space where eight works by sculptor Richard Serra are permanently displayed. Of the 24,000 square metres occupied by the Guggenheim Museum Bilbao, 11,000 are reserved for exhibition spaces. The architectural heart of the 20 galleries that make up the museum is the atrium, a large open space of curved volumes, surrounded by large glass curtain walls and crowned by a large skylight.