The Little Hagia Sophia Mosque, located in the old castle neighborhood, is a foundation work built in the Seljuk period, in the 13th century, in 1236. Built of rubble stone and cut stone in places, Küçük Ayasofya Masjid is a single domed building with a square plan. The dome, which uses segmented squinches as the dome transition element, was covered with lead in the later period. The building draws attention especially with the geometric ornament composition made of glazed bricks on the dome belly and the tile detail on the skirt. There are ornamental details around the window arch on the main façade of the building and on the surface of the inscription. The building is dated to the 13th century Seljuk period in terms of its architectural and ornamental features.