The Great Kilitbahir Castle (Kilitbahir means “lock of the sea”) rises in front of the Cimenlik Fortress on the picturesque shore of the Dardanelles. Both medieval castles were constructed by Mehmed II, known as Mehmed the Conqueror, an Ottoman sultan. They were supposed to control the ships sailing across the strait: they served really well over many years as nobody wanted to find themselves in the crosshairs.

Strong defensive wars of Kilitbahir were constructed in the shape of a shamrock. They surrounded the watchtower. Three stone bridges connected the tower to the walls, forming three semicircular courtyards. Despite numerous reconstructions since the reign of Suleiman I the Magnificent, the ancient castle's original design has almost completely survived to this day. The main tower of 30 meters high survived as well. Previously, it was crowned with a wooden roof in the cone shape, covered with lead plates. Today, there is a spacious observation deck on the roof’s place, which offers a wonderful view of the entire fortress.

Three gates led inside the fortress, one led from the sea. Some wall sections were hollow. They contained labyrinths of secret passages and weapons depots. Today, Kilitbahir Castle got the status of a museum, being the unique one with its ancient artifacts and wax figures. The museum opened in 2015 demonstrates the way of life of Turkish peasants who lived in the nearby village of Kilitbahir that took its name from the fortress. There is a separate exhibition in the museum dedicated to the activities of Piri Reis, an Ottoman navigator. The charming village of Kilitbahir is also worth visiting. It houses plenty of survived medieval monuments, a historical mosque, the ruins of two huge hammams, and many ancient fountains. Rumour has it that this is a burial place of the beautiful queen, Hecuba, the second wife of King Priam of Troy and the mother of Prince Paris.