Ghadamès, known as 'the pearl of the desert', stands in an oasis. It is one of the oldest pre-Saharan cities and an outstanding example of a traditional settlement. Its domestic architecture is characterized by a vertical division of functions: the ground floor used to store supplies; then another floor for the family, overhanging covered alleys that create what is almost an underground network of passageways; and, at the top, open-air terraces reserved for the women.