The Stavros Niarchos Foundation Cultural Center is a cultural center complex in the municipality of Kallithea in Attica which includes new facilities for the National Library of Greece and the Greek National Opera, as well as the 210,000 m² Stavros Niarchos Park. The center was designed by architect Renzo Piano and its construction was funded by the Stavros Niarchos Foundation. The $861 million project was completed in 2016, and was donated to the Greek state in 2017.