Siirt Grand (Ulu) Mosque The Siirt Grand Mosque, located in the city center of Siirt, was originally constructed in 1219 by the Iraqi Seljuk Sultan Mugizuddin Mahmut. The mosque's rectangular design is oriented east-west and features a space covered with three side-by-side domes on an octagonal drum, two vertical barrel-vaulted sections on the east and west sides of the domes, and one section with two transverse naves and a vertical nave to the north. Over the centuries, the mosque underwent significant renovations between 1229 and 1985, resulting in many alterations to the original structure. One of the most notable features of the Siirt Grand Mosque is its ornate minaret, which is divided into various decorative belts that narrow as they ascend. This style of minaret is reminiscent of those that were popular during the Seljuk and Atabek periods in Anatolia, though the glazed bricks that were commonly used during those times are not as prevalent on this particular minaret. The mosque was constructed using cut stone, rubble stone, brick tiles for decoration, and Khorasan mortar as the binding material. However, in the last century, the mosque became unrecognizable from the outside due to the construction of one and two-story reinforced concrete structures surrounding it. Fortunately, restoration work was completed between 2008 and 2013 as part of a conservation project prepared by the Bitlis regional directorate for foundations. Private property around the building continues to be expropriated, and repairs on the southern and western perimeter walls have been partially completed. Overall, the Siirt Grand Mosque remains an impressive example of Anatolian architecture with unique decorative features.