Direction sign spiritual bulwark

Quick answer：

The 'spiritual bulwark' of direction signs refers to the profound significance and symbolism behind these signs. Direction signs are essential for navigating through cities and providing information to travelers. The concept of a 'spiritual bulwark' suggests that these signs not only guide physically but also have a deeper, almost metaphysical role in the journey of individuals. This can be seen in their design, placement, and the information they provide, which can have a psychological impact on the traveler's experience.