The building is located outside the walled city of Sinjar, on an elevated hill next to the city gate and is attributed to Sittna Zaynab, Imam Ali's daughter. According to the inscription above the entrance door, the building was built by Badr al-Din Lu'lu' in 1239 as part of his ruling strategy to support Shi'ism through sponsoring the erection of several Imams' shrines between Mosul and Sinjar.
Sittna Zaynab mausoleum is composed of one big domed chamber measuring 5.4 by 3.8 square meters housing the sarcophagus built in stone and Juss. On the sarcophagus, some Quranic inscriptions are still visible. The tomb chamber has a small mihrab with no decorations and a conical ribbed dome visible from the outside. The interior walls and the dome surface are covered with Juss to prevent future deterioration except two corners of the dome where the original muqarnas decoration is still visible.
Next to the tomb chamber is a musalla or praying room accessible by a few steps and an arched doorway with inscriptions above. It is similarly roofed with a semi-circular dome ribbed from the outside that reaches seven meters in height. Its interior is decorated with three layers of muqarnas above a band of inscription. It houses a mihrab built in stone and juss (gypsum), and occupies the entire qibla wall. It is composed on two rectangles with colonettes on two sides. On the three sides of the mihrab, runs a line of calligraphy measuring a width of 8.5 centimeters decorated with high relief of geometric and floral motifs. Above this inscription band runs another one mostly fallen off that wraps around the musalls'a four walls.
Other rooms have been added to the original building. They have no major decoration; their internal walls are plastered with the exception of a marble inscription removed from the original building, and stuck on the addition for decorative purpose, mentioning the name of Badr al-Din Lu'lu'.
The building was severely destroyed during the Mongol invasion. It was restored later by the Mongol ruler Kowam al-Din Muhammad al Yazidi, to house the Friday prayer. A later restoration by the Pasha ben Khada dates to 1693.
Bosworth, Clifford Edmond. 1996. The New Islamic Dynasties. New York: Columbia University Press, 190-191.
Shumaysani, Hasan. 1983. Madinat Sinjar min al-Fth al-Arabi al-Islami Hatta al-Fath al-Uthmani. Beirut: Dar al-Afaq al-Jadidah.