The Beni Isguen to which Lieutenant d'Armagnac expects to travel is a medieval fortified oasis city in the heart of the Algerian Sahara, in a province known as Ghardaia. Today, visitors cannot enter the Mzabite city without an authorised guide. There is a strict dress code and photographs are forbidden there. There is no accommodation for visitors who must leave by nightfall. Igherm is the name of a village in the western Anti-Atlas Mountains in Morocco - too far to be the town in Algeria mentioned here. However, igherm is also the word of fortified granary and may have been used by Bowles as a probable name for a fictitious Saharan town in Algeria.