Situated away from the city's residential districts, the souks of Tunis are home to narrow yet extensive small shops standing one next to the other, where merchants and artisans are grouped together according to their speciality. Their precise location in the city is well organised: the most highly regarded occupations (perfume, silk weaving etc) can be found around the Great Mosque; the most polluting activities, such as tanneries, on the edge of the city; and lesser-skilled trades (e.g. food shops) outside of town. Here, bargaining is king, except on Fridays when the majority of shops are closed.