Ghardaïa (Arabic: ولاية غرداية ) is a wilaya in eastern Algeria. Capital of the wilaya is Ghardaïa. The city has a population of 110,724 (1998 census).It is the traditional heart of the M'zab valley, home of the Ibadi Muslim sect in Algeria, and has preserved its original medieval architecture remarkably well; the valley of which it forms a part is an official World Heritage Site.