Spain, Madrid, Cuatro Torres Business Area (CTBA), located along the Paseo de la Castellana; from left ro right the Torre Espacio by the architect Leoh Ming Pei, the Torre de Cristal by Inigo Ortiz, Enrique Leon and César Pelli, the Torre Sacyr Vallehermoso by Carlos Rubio Carvajal and Enrique Alvarez-Sala Walter and the Torre Repsol by Norman Foster