Bithynia Galleries
The galleries located under Bursa Castle were created by neatly carving out of a very resistant stone mass that forms the castle hill. These galleries; These are the ways used for the people to resist sieges, to store sufficient supplies and ammunition, and to sneak out of the castle in case of life-threatening situations. Bursa Tekfuri resisted the Ottoman principality for years thanks to this huge cave and tunnel system.