The Grand Mosque (Ulu Camii) The Grand Mosque of Erzurum, also known as the Atabey Mosque, is a significant religious site located in Erzurum, Turkey. The mosque, commissioned by Nasreddin Aslan Mehmed, the Emir of Saltuk, was built in 1179 and has undergone five restorations as noted by inscriptions. While some parts of the mosque have been partially changed due to repair work over time, including the dome and vaulting system, a portion of the qibla wall and a large section of the central aisle still stand after nearly 800 years. The rectangular-shaped mosque measures approximately 41 meters by 44 meters, and its main entrance is on the north side of the building. The east façade has two doors that provide ample light to the symmetrically arranged interior spaces around the windows. On Fridays and sacred nights, the mosque can accommodate up to 10,000 worshippers. The mosque is constructed of cut stone with timber used in the dome's construction, while the minaret shaft is made of bricks. The geometric motifs inside the mosque are typical of twelfth-century mosques. The simple stalactite mihrab niche's wide rectangular frame is intricately carved with a braided pattern of intersecting octagons. The minaret, attached to the northwest corner of the mosque, can be accessed through steps within the mosque and begins at the top of the wall.