Currently 55% of the world's population lives in cities, predictably reaching 70% in 2050. Cities are organisms in continuous transformation: growth, change, but also shrinking or collapse. Open City explores and speculates from contemporaneity about the future of the post-industrial city, where industrial archipelagoes (S), frames (XL) and obsolete or deprogrammed singularities (M/L) represent critical contexts but also opportunities for a new Open City.