Ancient walls, barbed-wire walls, metaphorical walls, political walls: all form, reform, and dissect our world. They mark sacred space and embody earthly power. They maintain peace and cause war. They enforce difference and create unity. Walls are pervasive and potent, and for Thomas Oles, it is time to broaden our ideas of what they can - and should - do. In Walls, ales asserts that our societies and our politics are shaped by - and shape - the divisions we make in and among landscapes. He traces the rich array of social practices associated with walls and other boundary markers across history and prehistory, and he describes how, at the dawn of the modern era, these practices were pushed aside by new notions of sovereign rights and private property. The consequences of this change can be seen all around us. From nation to parcel, landscapes everywhere today are divided and subdivided by boundaries whose poor material is matched only by their moral ugliness. Oles show that walls are relational, and all communities are defined both by and through them. The crafting of walls is therefore critical to defining our ethical relations to the landscape and to one another. In an insightful and evocative epilogue, ales brings to life a society marked by productive and thoughtful relationships to its boundaries, one that will leave readers more hopeful about the divided landscapes of the future.