 It is the second tallest building in Spain and the 4th tallest building in the European Union.Designed by Lord Foster, it was first known as Torre Repsol and would have served as headquarters for Repsol YPF oil and gas company.During the construction of the tower, Repsol decided to change the location of its future headquarters and the financial institution Caja Madrid purchased the building for €815 million in August 2007.