From Wikipedia: Tour EDF is an office skyscraper located in La Défense, the high-rise business district west of Paris, France.
The tower was built for Électricité de France (EDF), France's main electricity company, and hosts company's offices. Tour EDF is 165 m (541 ft) tall, the tallest skyscraper built in La Défense since the year 2000. Its ground shape is elliptical, with a maximum length of 70 meters (230 feet) and a maximum width of 32 meters (105 feet).
Tour EDF's most striking characteristic consists in the extrusion of a conic section of the tower on its northern edge. The resulting conic hole extends from the ground floor to the 26th floor and serves as the main entrance to the tower, an entrance built under a wide circular canopy 24 meters (79 feet) in diameter. As a consequence, the length of the tower is slightly shorter at its base than at its top.
The cladding of the tower alternates horizontal stripes of plain steel and tinted windows.