Uludag, the ancient Mysian Olympus, is a mountain in Bursa Province, Turkey, of altitude 2,543 m. It is a favourite center of winter sports, including skiing, and a national park of rich flora and fauna. Summer activities, such as trekking and camping, also are popular.

Turkish Uludag means "Great Mountain", but in colloquial Turkish, the mountain is called Kesis Dagi, "Mountain of Monks". It is said that Homeros used to refer to Mt. Uludag as Olympos Misios or Bithynik Olymp. According to the legends , it is said that Trojan wars used to have been watched by the Apollon and the other Greek Gods. In the Roman Empire and Hellenic periods, Mt. Uludag a place of seclusion for early Christian monks.

Mount Uludag is the highest mountain of the Marmara region. Its highest peak is Kartaltepe 2543 meters high. To the north are high plateaus: Sarialan, Kirazlıyayla, Kadıyayla, Sobra.