Shadow Territory examines the largly overlooked social world behind the construction of Switzerland's Grande Dixence dam. While the dam became a national symbol of technical mastery, much of the system that made it possible has remained out of view. This book draws attention to the temporary settlements and the labour arrangements that shaped the daily life across the construction sites. Based on archival work and field research, it traces the experiences of the thousand of mostly migrant workers who built the underground network feeding the dam. One of its key findings is that the settlements they inhabited were not simply temporary, but mobile spaces of discipline, in which the architecture of barrackhuts played an active role in structuring bodies, work, and routine, while leaving only faint material traces. Interpreting these traces as a territorial archive, Shadow Territory challenges romantic Alpine imagery and offers a quieter, more grounded account of the Alps as an industrial landscape. It calls for recognizing this forgotten labour as part of Switzerland's cultural heritage and for acknowledging the infrastructures that continue to shape land and life in subtle but lasting ways.