The Puerta de Europa towers (Gate of Europe or just Torres KIO) are twin office buildings in Madrid.
Each building is 115 m tall with an inclination of 15°, making them the first inclined skyscrapers in the world. They were constructed from 1989 to 1996. The Puerta de Europa is the second tallest twin towers in Spain.
They were designed by the American architects Philip Johnson and John Burgee, built by Fomento de Construcciones y Contratas and commissioned in 1996.