Contestations over indigene rights and political representation resulted in Christian-Muslim riots in the Nigerian city of Jos where, between 2001 and 2010, over 5,000 people were killed. This study complements existing literature on the spatial dimension of violence by focusing on how Jos’s neighborhoods were transformed from everyday residential areas to spaces of ethnic differentiation and violence. It employs an ethnographic study to map the emergence and development of ethnic strongholds and frontiers, two kinds of socio-spatial settings conceptualized to help explain the spread and patterns of violence across Jos’s neighborhoods.