["International Journal of Urban and Regional Research, EarlyView. ", "\nAbstract\nIndonesia's new capital city is designed to become a green and sustainable city. In this article, we examine the (un)sustainability of the process through which the city is coming into being. Using the sociospatial theory of planetary urbanization, we trace the dialectical relationship between the new city and sites beyond it to show how bringing a sustainable city into being in East Kalimantan requires other sites to become unsustainable. Through multi‐sited fieldwork in Kalimantan and in extraction locations in the adjacent province of Sulawesi, we demonstrate how the making of a sustainable city relies on an unsustainable process of rock extraction elsewhere, reproducing the operational landscape from Kalimantan to Sulawesi. This highlights the importance of translocal geography perspectives for understanding official claims of sustainability in the new city vis‐à‐vis the grounded realities of planned urban development that generate unsustainability in other places. In terms of theory, we foreground the role of temporality in analyses of planetary urbanization, as reflected in the geological time formation of mined rock transferred to the new city and in the current and future environmental risks incurred in the reproduced operational landscape.\n"]