Founded in the late 1960s on Chile’s Pacific coast, the Open City (la Ciudad Abierta) has become an internationally recognized site of cutting-edge architectural experimentation. Yet with a global reputation as an apolitical collective, little has been discussed about the Open City’s relationship with Chilean history and politics. Politics of the Dunes explores the ways in which the Open City’s architectural and urban practice is devoted to keeping open the utopian possibility for multiplicity, pluralism, and democratization in the face of authoritarianism, a powerful mode of postcolonial environmental urbanism that can inform architectural practices today.