Urban planners -whose disciplinary focus is the local, the spatial, and the practical -have been largely indifferent to the significance of religious difference in urban settings and seemingly unable to understand why religious diversity presents both problems and opportunities for the modern city.This Interface examines challenges that urban planners face in managing the complex and morally heterogenous cities of our contemporary secular age -an age in which urban environments are increasingly interconnected economically and yet fractured by religious contestation. We live at a particular socio-historical juncture when conventional notions of the public sphere face constant pressures, not only from the growing public influence of religion, but also from the secular anxieties that emergent religious claims generate. These interdependent forces have cast aside the facile prophecies of secularization theories -supposing that as modernity waxes, religion, in its public manifestation, wanes. Renewed religious and spiritual commitments to tackle social injustices of urban problems have also questioned old conceits that religion must be irrelevant in conventional planning deliberations.The question before us is less about how to avoid spatial manifestations of religious differences in planning, but more about how to rethink the relationship between religious convictions and planning actions in ways that move well beyond presuming the exclusionary stances of religiosity and the dismissive glances of professional planners.As spatial disputes that involve religious-secular entanglements have proliferated, so have urban planners become more involved in the religious and secular lives of the communities they serve. To explore these issues, we asked our Interface contributors to address one or more of these challenges:(1) First, local opposition to locational decisions can come from, or focus upon, claims invoking religion -or its absence. Examples include: opposition to the construction or expansion of religious spaces (e.g. a synagogue, mosque, or church) as well as religious opposition to practices of different faith groups (e.g. building a Muslim cemetery or a pagan temple) or to proposals that some religious groups consider 'places of vice or iniquity' (e.g. a casino or strip club). (2) Second, these spatial disputes often involve competing and parallel views of what counts as 'religious' and what constitutes a 'religious space.' How to practically steer through, not away from, such salient variations for planning purposes? (3) Third, how does one understand a phenomenon that is quietly but incessantly shifting the socio-spatial fabric of our cities, namely the spatial segregation, or voluntary withdrawal, of
