Sivrihisar Grand Mosque The Ulu Mosque, also known as the Sivrihisar Grand Mosque, is a historic mosque located in the town of Sivrihisar within Eskişehir Province in Turkey. It was built in 1231-1232 by Leşker Emir Celaleddin Ali during the reign of Anatolian Seljuk Sultan Kayqubad I. The mosque has undergone two restorations: the first in 1275 by Eminüddin Mikail bin Abdullah, regent of Kaykhusraw III, and the second in 1440 by Hızır Bey, a judge from Sivrihisar who later became Istanbul's first judge. The mosque is one of the five known examples of the wooden columned architecture technique. The mosque has a ground area of 1,485 square meters and features four entrances on its outer walls, allowing different prayer groups to enter through separate gates or doors. The roof is covered with tiles and has recently been replaced with lead sheet. Inside, the roof is supported by 67 wooden columns, with upper parts decorated with painted engravings of figures in green, red, and black. Some of the columns stand on stone bases believed to have originated from Pessinus, an ancient city now known as Ballıhisar located near Sivrihisar. The Sivrihisar Grand Mosque is a historic mosque situated in the town of Sivrihisar, in the province of Eskisehir. It is designed with six naves arranged in an east-west direction, with the middle two being higher than the others and resembling the traditional tents of Central Asia that were popular among nomads. One of the mosque's notable works of art is a minbar, crafted in 1245 by Horasanli Ibrahim Mehmet from walnut trees and decorated with intricate geometrical and floral designs. The minbar is believed to have been transferred from the Sivrihisar Kılıç Masjid, which was demolished in 1924. The top turret was added by Osman oğlu Hacı Habib in 1409-1410 as indicated by its inscription. The Sivrihisar Grand Mosque was added to the UNESCO World Heritage Tentative List on April 13, 2016, and is recognized for its historical significance and architectural uniqueness.