Some ramparts and walls still survive on the steep cliff that is the site of Bursa's citadel and its oldest neighbourhood, Tophane. Walk up Orhan Gazi (Yiğitler) Caddesi to reach the hisar (fortress). On the summit, a park contains the Tombs of Sultans Osman & Orhan, the Ottoman Empire's founders. Osman Gazi's tomb is the more richly decorated.

