Founder of the Ottoman dynasty Osman I and his son, Orhan, are buried in two rather modern constructions that nowadays attract huge crowds.

For once from the Ministry of Culture and Tourism: "The present tombs in Bursa of the original founders of the Ottoman state, Osman and Orhan, are structures erected in recent times. They were brought to a state beyond repair by the earthquake that leveled Bursa in 1855; following which time they were constructed in their present form after the complete removal of the original buildings. The original tomb buildings are known to have been, essentially, a centuries-old utilization of one or several very ancient Byzantine structures dating to the period prior to the conquest of Bursa. "

In accordance with his last will, Osman Gazi (1258-1326) was buried in the chapel of Saint Elie, in an old Byzantine monastery in Bursa (in the Hisar district). He died in 1326, shortly before or shortly after the Ottoman conquest of Bursa by his son Orhan, who had succeeded him as commander-in-chief in 1324. His tomb was renamed ‘Gümüşlü Kümbet’ (the Silver Dome) by the Turcs, because of the monastery’s shining domes, which were silver guilt; it was damaged by a fire in 1801, and completely destroyed by the earthquake of 1855.
Sultan Orhan’s tomb was built some years later, next to his father’s grave, inside the former Byzantine monastery; this ‘türbe’ too was ruined completely in 1855.
Both tombs were rebuilt by Sultan Abdülaziz in 1863, near their original location.

Correspondent: J.M.Criel, Antwerpen.
Sources: ‘Vakıf Abideler ve eski Eserler (volume III)’ - Vakıflar Genel Müdürlüğü, Ankara 1983
‘Bursa, the Living Museum’ – Ismail Cengiz, 2009 & Wikipedia .