The Zayn al-Din Minaret is named after Khwajah Zayn al-Din, a brother of Khwajah 'Imad al-Din who commissioned work on the Masjid-i Mir 'Imad in the 1460s. It is the only remaining part of what was once a larger structure that may have included a khanaqah. Its date of construction is not certain, with some authors attributing it to the Seljuq period.1
In its current form, the minaret is cylindrical shaft made of brick that rises to a height of 22 meters. Two bands of glazed tile divide the shaft into segments. Today's minaret represents half of the original tower, which was close to 47 meters tall. The top half, which included a cornice, was removed after 1923 as the minaret had been damaged in previous earthquakes and threatened to collapse.