Cuatro Torres Business Area (CTBA), is a business district located in the Paseo de la Castellana in Madrid on the former Ciudad Deportiva of Real Madrid. The area contains the tallest skyscrapers in Spain, and some of the highest in the European Union: the Torre Espacio, Torre de Cristal, Torre PwC and Torre Cepsa. Construction of the buildings finished in 2008. The complex was formerly known as Madrid Arena. These four skyscrapers constitute a business complex built on the grounds of the old Real Madrid sports complex. The four towers are the Foster Tower, the PWC Tower, Torre Cristal and Torre Espacio.