The city itself speaks of this as “One of the most important historical monuments of Sivrihisar District is the Treasurer’s Masjid. The interior of the mosque, which was built by Necibiddin Mustafa, who was the Treasurer of the Anatolian Seljuks (Minister of Finance), in 1274, is decorated with miniatures dating to the 15th century. Flowers, date trees and geometric motifs are among the miniatures of Mecca, Medina and Jerusalem. embroidered with colors. The bottom of the paintings are decorated with flower vases and decorative flowers in black, cobalt blue, earth green and brown.

The first example with a Kaaba motif, which is known to have been made as a fresco in Anatolia, is located in the Treasuredar Masjid. It is thought that the Nefesdar Masjid was used as a classroom by the students of the Treasurydar Madrasa, so it was devoid of a minaret and the Hoşkadem Mosque was built next to it. The graves of Esma Sultan, the sister of Necibiddin Mustafa and Emineddin Mikail, who had this mosque built, are located in front of the mosque.