After the first few months of the war, a relatively mobile conflict settled into the now infamous trench warfare experience so powerfully identified with World War I. Integrated with the trench system were other underground spaces soldiers inhabited for extended periods. These caves, the result of centuries of stone quarrying, were mini cities beneath the surface.
They were wired for electric lighting and communications equipment, and had other infrastructure for long-term occupancy. Beyond basic beds and furniture, the spaces had command centers, post offices, altars for religious services, even small theaters the soldiers used to create their own entertainment.
Photographs by Jeff Gusky