The shift from sail to steam in the mid-nineteenth century forced naval arsenals such as Brest to transform, with ministers in Paris kept informed of military port activity through the output of photographic workshops, images that were essentially documentary in purpose, though their anonymous authors drew on the arsenal's austere architecture to build images of great formal rigour. Far from mere nostalgia for a vanished industrial urbanism, these photographs interrogate the memory of the city and territory, tracing a map around the Penfeld river that reveals how the city took shape across the nineteenth century, the photographs unfolding from bank to bank to locate the arsenal's different centres of activity.