Puerta de Europa is a major mixed-use development in the center of Madrid that includes two office buildings and two residential buildings with ground-floor retail space. The project is adjacent to the Paseo de la Castellana, one of Madrid's most important boulevards.

The location of the site over a subway interchange made it structurally impossible for office buildings to stand near the street. In order for the two towers to read as a pair and to insure their visibility from up and down the Paseo, they were designed to lean toward each other over their plazas. The exterior skin of each tower is a composition of a major structural grid of rectilinear and diagonal members clad in stainless steel. A fine red line contrasts with the steel, and these elements stand forward from the taut custom gray-glass curtain wall. Jeff Sydness was the design partner of John Burgee Architects for the project.