The Pirelli Tower or Pirelli Building (Italian: Grattacielo Pirelli - also called "Pirellone", literally "Big Pirelli"), is a prominent building in Milan, Italy. In 1950, Alberto Pirelli, the president of the Pirelli Company, ordered that a skyscraper be built in the area where the corporation's first factory was located in the 19th century. The project was developed by architect Gio Ponti, with the assistance of Pier Luigi Nervi and Arturo Danusso. At 127.1 meters (417 feet), it is the second tallest building in the city and was built of concrete of about 70,000 tons. Construction of the tower began in 1956 when Italy was experiencing an economic boom. The tower was to be surrounded by low lying buildings on a pentagonal plot of land. Upon its completion in 1958, it became a symbol not only of Milan, but also of the national economic development. The building was later sold to the Lombardy region, of which it's now the head office. Characterized by a bold structural skeleton, smooth refined curtain wall façades, and tapered sides like the bow of a ship, it was among the first skyscrapers to abandon the customary block form. Until recently, it was the tallest building in Italy. The architectural historian Hasan-Uddin Khan praised it as 'one of the most elegant tall buildings in the world' and as one of the 'few tall European buildings [that made] statements that added to the vocabulary of the skyscraper'. Some architectural critics believe that the Pirelli building was the inspiration for the design of the Pan Am Building (now MetLife Building) in New York and Alpha Tower in Birmingham.