According to the Ait Hdiddou tribe, which consists of two parts the Yaazza Ait and Ait Brahim, the youth of the tribe organize a collective celebration of marriage at the end of every summer. The festivities start when the harvest is finished.
The story begins with two young people in love. Her name was Tilsit, his was Isli. They had been denied permission to be together because of the animosity between their respective tribes and subsequently they drowned themselves in the two lakes that still bare their names today. But their story did not end there. They were unable to unite in death, as the mountain that separates the two lakes also separates their spirits, leaving them to yearn for each other in death as they had in life. After this tragic event, families of the different tribes decided that both men and women would be able to choose their own life partner. With this cautionary tale in mind, all prospective newly weds are said to visit the tomb of a local holy man, who became famous for blessing successful marriages.
This is the story of Imilchil where an annual pilgrimage of young people in search of a partner occurs every year after the harvest in September, as they are normally cut off from the outside world during most of winter due to the snowfall.
The Berber word Imilchil, ''Imi n Lkil'' in Berber and "Foum El Kail'' in Arabic, mean "provision door", because the place of the moussem was formerly used as a trading market for certain agricultural products and crafts between the two slopes of the Atlas. The festival takes place amidst an enormous encampment, surrounded by the hills of this arid region.