One of the things that attracts my attention in cities all over are the leftover spaces where things were once made. The faded grit and glory of a city’s formerly industrial buildings and districts have an aesthetic appeal in their decay—a theme that has attracted many an artistic and entrepreneurial eye. Perhaps because of this appeal (along with their general undesirability and low rents), the buildings that once housed large-scale manufacturing, warehousing, markets, and other functions of a city’s industrial past have over time frequently become homes for new types of creative and productive activity. Spaces and places that appear to be neglected and disused are often teeming with new life. With little or no renovation, generations of artists, workers, small businesses–producers of all kinds of things–have moved into cities’ industrial lofts, warehouses and factories, either alongside or replacing more traditional industries. In this way, the industrial infrastructure of so many cities has provided ongoing support for growth and innovation, even while larger interests and policies assume these spaces and activities are dead.