Ottoman fortresses were military structures built by the Ottoman Empire from the 14th to the 17th centuries. They served to protect strategic locations, control trade routes, and defend against invasions. These fortifications often featured thick walls, towers, and moats, showcasing advanced architectural techniques of the time. Many of these fortresses, such as Rumeli Fortress in Istanbul and Kale Fortress in Albania, played crucial roles in military campaigns. Today, they stand as historical landmarks, reflecting the empire's military prowess and architectural heritage, attracting tourists and historians alike.