This is the Mansur Baba Türbesi. The tomb was demolished when in 1234 the Seljuks conquered the city. It was restored along the lines of the original. Of four graves found inside two are supossed to belong to Imadeddin Ebubekir and his son, Nizameddin Ibrahim, two rulers belonging to the Artuk dynasty that was overthrown by the Seljuks.