Skyscrapers

• PPG Place

  Beautiful PPG Place is the headquarters for PPG Industries, Inc. and perhaps the most distinctive building in Pittsburgh's picturesque skyline. PPG Place, a large building complex including a 40-story tower (635 feet) with five satellite buildings that cover a six city block area, was designed by Philip Johnson and John Burgee. The large urban complex was in part inspired by two existing architectural landmarks in Pittsburgh, the Cathedral of Learning in the University of Pittsburgh's campus and H.H. Richardson's Allegheny County Courthouse (both worth visiting when in Pittsburgh).

  In PPG Place, Johnson made loose use of Gothic architectural vocabulary, translating it into modern materials and construction techniques. PPG Place stands perhaps as one of Johnson's buildings that best demonstrate his wit and affinity for mixed messages. By mixing historical forms with modern methods of construction, Johnson created a post-modernist building which is truly unique, in part due to its use of materials, which were immensely appropriate since PPG is a leading manufacturer of curtain wall assemblies.

• Regional Enterprise Tower

  Designed by Harrison & Abramovitz and erected in 1953, the Alcoa Building is a 30-story advertisement for aluminum. The curtain wall is made of prefabricated sections of aluminum panels that contain the windows, set in rubber gaskets, and the floor area. Eventually the company outgrew it, and in 1998 then-Alcoa chairman Paul O'Neill donated the building to the cause of regional enterprise development. Now known as the Regional Enterprise Tower, the original Alcoa building on its first floor is home to Xplorion, an exhibit that offers weekday, virtual tours of southwest Pennsylvania destinations and online access to more than 1,200 regional information resources. Visitors can custom-design their tours, "flying" over a digital map of the city and dropping down at attractions of their choosing.

• U.S. Steel Tower

  Also designed by Harrison & Abramovitz, the world headquarters of the U.S. Steel Corporation was completed in 1971. During the initial planning stages, the U.S. Steel Corporation seriously considered making this development the world's tallest building. The tower's shape, mirroring the shape of Downtown Pittsburgh, is a triangle with indented corners. It was the first building to use liquid-fireproofed columns. At the time of its completion this was the world's tallest building outside of New York and Chicago, and is still the tallest building in Pennsylvania. When its construction was completed in 1971, the building was considered to be an engineering masterpiece.