The mausoleum (türbe) called Kirgizlar (The Kirghiz) is located outside the Yenisehir Gate of Iznik alongside ruins of the Orhan Gazi Mescid and Soup Kitchen, soon after the Ottoman conquest. Estimated to belong to the same period, the mausoleum was probably built to honor warrior-mystics from Central Asia who were involved in the conquest and its aftermath.
The mausoleum consists of a domed grave chamber preceded by a portal eyvan to the north. The eyvan, currently entered through a door, was originally open on the north. Its barrel vault has since collapsed. A door, framed with molded marble fragments of Byzantine origin, leads into the lofty grave chamber. The room is crowned by a conical dome on pendentives raised by means of a tall dodecagonal drum. Six windows on the east, west and north walls, a single window on the south wall and four additional windows on the drum of the dome illuminate the room. Inside the drum and the dome, sections of colored painted decoration remain visible.
The grave chamber houses eight sarcophagi of various sizes with no inscriptions; there are six more graves in the eyvan. The walls of the building were built using two layers of brick between two or three layers of stone and are capped with saw tooth brick cornices. The brick dome is covered with terra-cotta tiles.
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