As social creatures, Wraiths need some sort of central meeting place. They need somewhere that they can meet, talk, do their business or just relax, and it would be best if this took place in a secure environment. Meanwhile, the more pious - or dutiful - amongst them also need a place to pay homage to their Gods

Such places are generally known as Citadels and Temples, and their ownership is hoarded by the Concords as signs of strength, and sources of power. Under normal circumstances, these structures provide a framework for the social structure within a Concord. And when the Storms hit, everyone who's far from their own Haunts heads for their own Citadel, both to keep it safe from the Damned, and possibly save their own lives.