In international terms, Sunila, which was designed by architect Alvar Aalto, is the best-known architectural site in the Kotka-Hamina region. It is also the most extensive of Aalto’s realised designs. Once acclaimed as the most beautiful factory in the world, the Sunila Mill and its surrounding residential area became an icon of Aalto’s international modernism, presented at the World’s Fairs in Paris in 1937 and New York in 1939. This extensive and uniform residential area in Karhula, Kotka, is instantly recognisable as the handiwork of Aalto.