La Caja Mágica ("The Magic Box'"), also known as the Manzanares Park Tennis Center, is a sports structure located at the Park Manzanares, used for the Madrid Masters tournament in Madrid, Spain. Madrid’s Olympic Tennis Centre, designed by leading French architect Dominique Perrault, was inaugurated in 2009. There are three courts under the one structure, and a series of retractable roofs. The main stadium has a seating capacity of 12,442.