Within a city quarter, byroads lead towards individual building complexes or clusters of houses. The individual house is frequently also oriented towards an inner atrium, and enclosed by walls, which mostly are unadorned, unlike European outward-oriented, representative facades. Thus, the spatial structure of a medina essentially reflects the ancient nomadic tradition of living in a family group or tribe, held together by asabiyya, strictly separated from the "outside". In general, the morphology of an Islamic medina is granting—or denying—access according to the basic concept of hierarchical degrees of privacy. The inhabitants move from public space to the living quarters of their tribe, and onwards to their family home. Within a family house, there are again to be found common and separate spaces, the latter, and most private, usually reserved for women and children. In the end, only the family heads have free and unlimited access to all rooms and areas of their private home, as opposed to the more European concept of interconnecting different spaces for free and easy access. The hierarchy of privacy thus guides and structurizes the entire social life in a medina, from the caliph down to his most humble subject, from the town to the house.