Orhan Gazi put emphasis on landscape and city planning.
Following the conquest of Iznik, the Ayasofia Church in Iznik was converted to a mosque in
1331. In 1333 the first Ottoman mosque, Haci Ozbek was built. The other
monuments built in Orhan Gazi's period are, Iznik Hacı
Hamza Mosque and Dome, Iznik Green Mosque, Bilecik Orhan Mosque, Bilecik Orhan Gazi Imaret
(Hospice), Gebze Orhan Mosque, Bursa Orhan Mosque, Iznik Sultan Imaret (Hospice). Beside
these, he established a school, in Bursa.