Ghardaïa (Arabic: غرداية, Mzab-Berber: Taɣerdayt) is the capital city of Ghardaïa Province, Algeria. The commune of Ghardaïa has a population of 93,423 according to the 2008 census, up from 87,599 in 1998, with an annual growth rate of 0.7%. Ghardaïa is part of a pentapolis, a hilltop city amongst four others, built almost a thousand years ago in the M’Zab valley. It was founded by the Mozabites, an Ibadi sect of the Amazigh Muslims. In her 1963 book, La Force des choses, the French existentialist philosopher Simone de Beauvoir described Ghardaïa as "a Cubist painting beautifully constructed".