Risky facilities provide opportunities for the prevention of crime at risky places. What characteristics do the high crime facilities possess that are not present at facilities with lower rates of crime? It is these characteristics that offer the most promising explanations for these crime discrepancies. In this lecture, we argue that the distribution of crime across a population of similar facilities follows a J-curve: a few of the facilities account for most of the crime in these facilities. We revisit some of the explanations for risky facilities; examine measurement problems associated with studying them; list policy options; and conclude by exploring the hypothesis that crime concentration among groups of homogeneous facilities may be the outgrowth of complex dynamic interactions among individuals–offenders, targets, and place managers.