After the conquest of Istanbul, Mehmet the Conqueror chose a site on the Forum Tauri - Beyazit Square for his first palace. So called "Old Palace" is referred to in the sources as a walled complex, altough no traces of it now remain. It features, however in some old maps and plans of Istanbul, on the site of the present University Of Istanbul main building.It is though that the walls surrounding the university building follow the original walls of the palace, while the main portal is thought to have been where the present entrance is. Another portal looked out to Süleymaniye Mosque.