Skyscrapers Architects Frederick J. Osterling

The Commonwealth Building, originally known as the Commonwealth Trust Bank, is a 300ft (91m) tall skyscraper in Pittsburgh. It was completed in 1906 and has 21 floors. It is tied with the The Carlyle and Washington Plaza for 26th tallest building in the city.

The Union Trust Building (501 Grant St., downtown Pittsburgh, Pennsylvania), was erected in 1915-16 by the industrialist Henry Clay Frick. The Flemish-Gothic structure's original purpose was to serve as a shopping arcade.The building is modeled after the famous Municipal Hall at Louvain, Belgium, partly destroyed by the Germans. Known as the Union Arcade, it featured 240 shops and galleries. The mansard roof is adorned with terra cotta dormers and two chapel like mechanical towers.