Islamic architecture looks the epitome of perfection, with its white walls, its graceful minarets, its regularly-patterned tiles and the grand design of its mosques. Yet it cannot be perfect. Only Allah is capable of creating perfection, so all Islamic art and architecture must contain within it some flaw or imperfection, no matter how small it may be.
The other notable fact about Islamic architecture is that it allows for no representation of any human or animal form. There are no icons such as you find in Byzantine churches, and no statues such as are widely used in the Christian religion. In fact the Koran does not make any specific reference to banning such objects, but it is understood as part of the religion that no Muslim man would ever seek to make a representation of the Prophet Mahomet. By disregarding such statues and paintings, Islamic buildings are seen to be even more graceful, and this applies to domestic Islamic architecture, not just to the religious architecture which is what most visitors see, and want to see.
Muslim homes are built around a central courtyard, and you will not glimpse these as you pass by in the street. The Islamic entrance is designed to shield the courtyard from the gaze of passers-by, as it is here that the women of the house can relax or work unveiled. In Tunis it is the exception rather than the rule, to see a veiled woman (Bourguiba regarded them as demeaning), but the architectural principles still hold. The rooms of the house surround the courtyard, looking in on them, with no windows on the outer walls, appearing to turn their back on the public world.
What the visitor will see are the elaborate and large wooden doors on many houses, marking the boundary between that public world and the private world of the family. Most such doors have a knocker in the shape of a hand. This is the hand of Fatima, the Prophet’s daughter, acting to protect the house.