The Kurşunlu (usually indicating a mosque has a leaden roof) Camii. A notice indicates the mosque was made by Baba Yusuf. The date is given as 898 which I think translates to about 1493. The Belediye has, translated: Kursunlu Mosque
The mosque in the town center was built by Sheikh Baba Yusuf. According to its inscription, the date of construction is 898/1492. Sivrihisarli Sheikh Baba Yusuf's II. It is stated that he inaugurated the Bayezid Madrasa and gave the opening lecture at the first Friday prayer at the Bayezid Mosque. Baba Yusuf, born in Sivrihisar, is referred to by the nickname "Sivrihisari" in the sources, referring to his place of birth.