Qasr is an Arabic word for “castle,” and haj meant a pilgrimage. The haj is the annual pilgrimage undertaken by Muslims to Mecca, a trip that ideally has to be done by all Muslims at least once in their lifetime. During the 12th century, the Qasr Al Haj was a place where pilgrims who went on the haj stored their things before they went, like modern airport locker rooms or bank vaults, so they won’t be weighed down with too many things during their trip.
Qasr Al Haj was later used as communal granary and olive oil storage rooms, for villagers who did not have enough space at home to store these staples. The building originally comprised of 114 chambers, that corresponded to the number of chapters in the holy Koran. Each family had a space in that Qasr where they could keep food and grains for safe keeping. The qasr was in use even as late as the 1960s.