The former Van Nelle Factory (Dutch: Van Nellefabriek) on the Schie in Rotterdam, is considered a prime example of the International Style based upon constructivist architecture. It has been a designated UNESCO World Heritage Site since 2014. Soon after it was built, prominent architects described the factory as “the most beautiful spectacle of the modern age” (Le Corbusier in 1932) and “a poem in steel and glass” (Robertson in 1930).