Thought to have been built during the 17th century AD for the defence of the city of Hail, it is built on a hill with the same name in the centre of the city. Further additions and restorations have been made until it has assumed its current rectangular shape of approximately 40m x 11m in size. It had openings including watchtowers and windows (Turma) to be used by soldiers to sight any approaching hostile forces as well as a residential area, a mosque, baths, prayer places, toilets, warehouses and other facilities allowing citizens to live there for long periods.
