CTBA Is a business park near the Paseo de la Castellana in Madrid, on the grounds of the former Ciudad Deportiva Real Madrid. Originally known as Madrid ArenaThe consortium of the four towers owners decided to adopt a new corporate image for the set and the name CTBA. This business park consists of four skyscrapers that are the tallest buildings in Madrid and Spain. The four buildings are Caja Madrid Tower, the Tower Sacyr Vallehermoso, the Torre de Cristal and Torre Espacio. The first is the highest in Madrid and Spain with its 250 meters high.

The skyscrapers housing offices. However Sacyr Vallehermoso Tower also houses a hotel and at the top of the glass tower and a garden. Each tower has several floors of parking underground, and also underground, road access to the business park to avoid traffic crashes on the surface. The construction of these four buildings began in 2004 and in late 2007 and early 2008 were completed. Besides the four towers and within the precincts of the business park will be located on International Convention Center in Madrid, a conference building with 70,000 m² and a main auditorium with capacity for 3,500 people. The design of this building has been assigned to Emilio Tuñón after the final verdict of the jury of the contest held on 26 April 2007.