Ebu İshak Kazeruni (Ibrahim b. Şehriyar, 963-1035) was a famous Sufi born and died in Kazerun near Shiraz, eponym of the Ishaqiyya/Kazeruniyya order. The structure in a bastion of Erzurum castle is a lodge founded in his name; per historian İ.H. Konyalı he himself is buried in Kazerun — the Erzurum site is a MAQAM/lodge-tomb (the grave inside is locally attributed to 'Seyyid Ali'). Restored by the Ministry of Culture in 2006. (Sources: Erzurum Encyclopedia; Kültür Portalı)