It was built to a design by the architects Portaluppi, Muzio, Magistretti and Griffini, and decorated on the façade with bas-reliefs by Arturo Martini. Winner of the 1937 competition, the project for the Arengario concluded the process of urban renewal of the center of Milan, set by the architect Giuseppe Mengoni who had given a monumental character to the area around the Duomo. The Arengario was in fact built after the demolition of the Manica Lunga of Palazzo Reale, concluding the construction of the new Piazza Diaz. After a period of abandonment after the war, in the 1950s it was renovated and used as municipal and provincial offices. Since December 2007 the restoration work has been sponsored thanks to Urban. Worth mentioning is the installation of the first medium-sized Italian façade: a 487 m2 LED screen called MIA (Milano Alto).