Which city's coat of arms is depicted on the emblem of Alfa Romeo cars?

Alfa Romeo Automobiles S.p.A. is an Italian premium car manufacturer and a subsidiary of Stellantis. The company was founded on June 24, 1910, in Milan, Italy. "Alfa" is an acronym of its founding name, "Anonima Lombarda Fabbrica Automobili." "Anonima" means "anonymous", which was a legal form of company at the time, as it was founded by anonymous investors. In the initial set-up phase, in order to have a building to produce cars, the company bought the Portello factory building of Darracq in Milan, which was closing up and selling all assets. The brand is known for sport-oriented vehicles and has been involved in car racing since 1911.

In June 1910 the Società Anonima Darracq became Anonima Lombarda Fabbrica Automobili, and was readying its first model, the 24 HP. The board asked chief engineer Giuseppe Merosi to devise a badge for the radiator shell of the new car; Merosi turned to his collaborators. One of them, Cattaneo, was inspired by the coat of arms he had seen on the gates of Castello Sforzesco to include the biscione in the logo. Merosi liked the idea, and together with Cattaneo came up with a sketch, then approved by managing director Ugo Stella; Cattaneo was entrusted with doing the final design.