The fastest growing kind of public space in America is prisons. More jails are being built than housing, hospitals, or schools. No matter how well designed or brightly painted they may be, prisons are still closely guarded, built as cheaply as possible, and designed for surveillance. I can think of more pleasant public spaces, especially parks that I use in New York City. But is the Hudson River Park, near Battery Park City, or Bryant Park, on 42nd Street, less secure or exclusive than a prison? They share with the new wave of prison building several characteristics symptomatic of the times. Built or rebuilt as the city is in severe financial distress, they confirm the withdrawal of the public sector, and its replacement by the private sector, in defining public space. Reacting to previous failures of public space-due to crime, a perceived lower-class and minority-group presence, and disrepair-the new parks use design as an implicit code of inclusion and exclusion. Explicit rules of park use are posted in the parks and enforced by large numbers of sanitation workers and security guards, both public and private. By cleaning up public space, nearby property owners restore the attractiveness of their holdings and reconstruct the image of the city as well.